Calculators & Converters
Free online calculators and unit converters for finance, health, math, science, home improvement and everyday questions. Every calculator runs entirely in your browser — instant results, no signup, nothing sent to a server.
From a quick percentage to a full mortgage amortisation schedule, this is the largest collection of free online calculators and unit converters on Gera Tools — covering finance, health and fitness, maths, physics, chemistry, cooking, construction and dozens of everyday questions. Each one is a single-purpose calculator that gives you an exact answer instantly, shows the formula it used, and never asks you to sign up.
Every calculator runs entirely in your browser. Your numbers are never uploaded to a server, stored, or logged — which makes these tools safe for sensitive figures like salary, loan balances or medical values. Search by name above to jump straight to the calculator you need, or browse the grouped sections below.
Business & Marketing
Bow Arrow Kinetic Energy & FOC Calculator
Calculate arrow kinetic energy, momentum, and front-of-center balance.
D&D Ability Score Optimizer
Arrange D&D standard array or rolled stats for any class
D&D Carrying Capacity Calculator
Know exactly how much your D&D character can carry
Electrical Panel Load Audit Tool
Flag overloaded circuits, undersized conductors, and missing AFCI/GFCI per NEC 2023
FM Synthesis Carrier:Modulator Ratio Calculator
Find harmonic and inharmonic C:M ratios for FM synthesis timbres
Grounding Electrode System Resistance Calculator
Estimate ground-rod resistance with the Dwight formula for single and parallel rods.
Italy INPS Contribution Calculator
Estimate INPS for employees and gestione separata freelancers
LDR Voltage Divider Calculator for DIY Electronics
Calculate the series resistor value for a light-dependent resistor voltage divider
Solar Array Tilt & Azimuth Output Calculator
Estimate how tilt angle and compass orientation change a PV array's annual energy yield.
Water Hammer Arrestor Sizing Calculator
Select a water hammer arrestor size (A–F) per PDI-WH 201 by fixture load
Aldosterone-to-Renin Ratio (ARR) Calculator
Screen for primary aldosteronism from aldosterone and renin
Bone Marrow Blast Percentage Calculator
Calculate blast % from a differential count for AML/MDS diagnosis
Electrical Apprentice NEC Code Study Calculator
Practice NEC load problems with step-by-step solutions and a running score.
Electrical Conduit Bending Calculator
Stub-up, 90, offset, saddle, and back-to-back bend marks for EMT and rigid
Electricity Cost Calculator
Calculate daily, monthly and annual electricity cost for any load from wattage and utility rate.
Electrical Demand Charge Calculator
Estimate monthly demand charges from peak kW and find peak-shaving savings
Fuse vs. Circuit Breaker Comparison Tool
Compare clearing times of current-limiting fuses and breakers at any fault multiple.
Grounding & Bonding Checklist Generator (NEC 250)
Generate a site-specific NEC Article 250 grounding and bonding checklist
Electric Heat Trace Sizing Calculator
Size pipe heat trace cable wattage per foot for freeze protection at design ambient
Electrical Permit Load Summary Generator
Generate a permit-ready load summary sheet for AHJ submission from circuit data.
Electrical Safety Clearance Distance Calculator
Look up NFPA 70E shock approach boundaries for qualified and unqualified workers
Electrical Wire Cost Estimator
Estimate material cost for a wire pull from AWG, insulation type, footage, and price
Electricity Grid Carbon Intensity Tool
Look up CO2 per kWh for 40+ national electricity grids
Electrophoresis DNA Ladder Band Size Estimator
Estimate band sizes from gel image using ladder migration distances
IPG Strip pH Range Selector for 2D-PAGE
Match protein pI to the correct IEF strip pH range for 2D electrophoresis
Material Removal Rate (MRR) Calculator
Calculate cubic inches per minute removed in milling or turning
Peptide Molecular Weight & Isoelectric Point Calculator
Compute MW and pI from a one-letter amino acid sequence
Nutritional Requirements Calculator (Harris-Benedict / Mifflin)
Total daily energy and protein needs for clinical nutrition
Runway Length Required Calculator
Estimate factored takeoff and landing field lengths from performance inputs
Solar Array Shading Loss Estimator
Estimate annual PV energy loss from a tree, ridge, or chimney by sun-path geometry
Spectrophotometry Absorbance to Concentration Calculator
Apply Beer-Lambert for single readings or a standard curve
Stick Electrode Selection Guide
Match SMAW electrode type to base metal, joint position, and penetration need
Meat Roasting Time Calculator
Roasting times and safe internal temperatures by weight and doneness.
Electricity Bill Estimator
Turn watts and hours into a daily, monthly and yearly cost.
Electricity Cost Calculator
Add every appliance, set your tariff, and see daily, monthly and yearly running costs.
Contribution Margin Calculator
Instantly find your CM per unit, CM ratio, break-even point and operating leverage.
Current Ratio Calculator
Instant liquidity analysis: current ratio, quick ratio, cash ratio and net working capital.
EBITDA Calculator
Calculate EBITDA, margins, EV/EBITDA, and key leverage ratios instantly.
Economic Order Quantity (EOQ) Calculator
Find the optimal order size that minimises total inventory cost.
Payback Period Calculator
Find how long until your investment breaks even — simple and discounted methods.
Quick Ratio Calculator (Acid-Test)
Instantly measure short-term liquidity — does your business have enough liquid assets to cover current debts?
Return on Assets (ROA) Calculator
Measure how efficiently a business turns its asset base into profit.
Return on Equity Calculator
Calculate ROE — basic, DuPont 3-factor and DuPont 5-factor decomposition.
Working Capital Calculator
Measure liquidity: current ratio, quick ratio, cash conversion cycle and more.
Debt-to-Equity Ratio Calculator
Compute D/E ratio, net leverage, debt ratio and interest coverage from a balance sheet.
Electric Field Calculator
Solve E = k·Q/r², V = k·Q/r, F = qE and Gauss's Law with full working shown.
Photoelectric Effect Calculator
Calculate KE, stopping voltage, threshold frequency and wavelength using Einstein's equation KE = hf − φ.
Burn Rate & Runway Calculator
Know exactly how long your cash will last — and what to do about it.
Customer Acquisition Cost (CAC) Calculator
Calculate blended CAC, LTV:CAC ratio and payback period by channel.
MRR Calculator
Calculate Monthly Recurring Revenue, ARR, LTV and forward projections.
A/B Test Significance Calculator
Know whether your experiment result is real — two-proportion z-test with p-value, confidence interval and power check.
ARR Calculator
Calculate Annual Recurring Revenue, NRR, GRR and MRR bridge in seconds.
Average Order Value Calculator
Calculate AOV, compare periods and find the AOV needed to hit a revenue target.
CAC Payback Period Calculator
Find out how many months it takes to recover your customer acquisition cost.
Churn Rate Calculator
Calculate customer churn, MRR churn, LTV, and cohort retention — all in your browser.
Click-Through Rate (CTR) Calculator
Instantly calculate CTR, CPC, CPM, conversion rate and ROAS from your campaign data.
Conversion Rate Calculator
Calculate CVR, ROAS, CPA and test A/B significance in one place.
Cost Per Acquisition (CPA) Calculator
Calculate CPA, LTV, ROAS, CTR, payback period and campaign ROI in one place.
CPC Calculator — Cost Per Click, CTR, ROAS & CPA
Work out your CPC, CTR, CPM, CPA, ROAS and campaign profit in one place.
CPM Calculator
Calculate CPM, total ad spend, or impressions — plus CTR, CPC, CPL and ROAS.
Customer Lifetime Value Calculator
Calculate LTV, LTV:CAC ratio and CAC payback period instantly.
Customer Retention Rate Calculator
Calculate CRR, churn rate, and LTV from your customer counts — single period, trend, or industry benchmark.
Email Open Rate Calculator
Calculate open rate, CTR, CTOR, bounce rate and A/B significance for any email campaign.
Engagement Rate Calculator
Calculate ER by reach, followers, impressions or views — with platform benchmarks.
Gross Merchandise Value (GMV) Calculator
Calculate total marketplace transaction volume, take-rate revenue and net revenue across periods.
LTV to CAC Ratio Calculator
Measure unit economics — how much a customer is worth vs. what it costs to acquire them.
Net Promoter Score (NPS) Calculator
Calculate your NPS instantly from group counts or raw 0–10 survey responses.
ROAS Calculator
Calculate Return on Ad Spend — instantly see ROAS, break-even, POAS and net profit.
Startup Runway Calculator
See exactly how many months of cash you have left — and when revenue covers burn.
Bounce Rate Calculator
Calculate your bounce rate, engagement rate and improvement projection — instantly.
Monthly Active Users (MAU) Calculator
Track MAU growth, churn, stickiness and 30-day retention across multiple periods.
Viral Coefficient Calculator
Calculate K-factor and model exponential growth wave by wave.
Tax & Wages
VAT & Sales Tax Calculator
Add or remove VAT, GST or sales tax for any country.
Take-Home Pay & Salary Tax Calculator
Net salary after income tax and social contributions — UK, US, Germany.
Georgia (GEL) Salary & Take-Home Pay Calculator
Net salary after Georgia's flat 20% income tax and 2% pension.
Bangladesh Income Tax Calculator (FY 2024-25, NBR)
আয়কর হিসাব করুন — calculate your Bangladesh income tax instantly.
Saudi Arabia & UAE VAT Calculator (GCC) — Arabic RTL Friendly
Add or extract VAT for Saudi Arabia, UAE, Bahrain and Oman — with Arabic RTL layout.
Saudi Expat Income Calculator
Saudi take-home: no income tax, GOSI social-insurance deductions
Florida Payroll Take-Home Calculator
Calculate Florida net pay with zero state income tax
Texas Payroll Take-Home Calculator
Calculate Texas net pay — no state income tax, just federal plus FICA.
Washington State Payroll Calculator
Calculate WA net pay including PFML and LTI premiums
China VAT Calculator — 13% / 9% / 6%
Calculate Chinese VAT (增值税) at 13%, 9% or 6% by industry, both ways.
Ethiopia VAT Calculator
Add or extract Ethiopia's 15% VAT — flags zero-rated and exempt items.
Excavation Cut & Fill Volume Calculator
Estimate cut and fill earthwork volumes for grading or foundation work
Norway MVA (VAT) Calculator — 25% / 15% / 12%
Calculate Norwegian MVA at the 25%, 15% or 12% rate in both directions.
Saudi Arabia VAT Calculator (15%)
Add or extract Saudi 15% VAT in both directions with a full breakdown.
Thailand VAT Calculator
Add or extract Thailand's 7% VAT — instant result in your browser.
TIG Tungsten Size & Prep Calculator
Select the right tungsten diameter, alloy, and tip prep for any TIG weld
UAE VAT Inclusive/Exclusive Calculator (5%)
Add or extract the UAE 5% VAT component in both directions instantly.
Alaska Payroll Calculator
Calculate Alaska net pay — no state income or sales tax
Nevada Payroll Calculator
Calculate Nevada net pay — no state income tax, MBT applies to employers
New Hampshire Payroll Calculator
Calculate NH net pay — wages untaxed, investment income tax abolished 2025
South Dakota Payroll Calculator
Calculate South Dakota net pay with no state income tax
Tennessee Payroll Calculator
Calculate Tennessee net pay — no state income tax on wages
Wyoming Payroll Calculator
Calculate Wyoming net pay — no state income tax or estate tax
Albuquerque Minimum Wage & Overtime Calculator
Calculate Albuquerque hourly and weekly pay at the local $12.00/hr minimum
Atlanta Minimum Wage & Overtime Calculator
Calculate Atlanta hourly and weekly pay at the local $7.25/hr minimum.
Austin Minimum Wage & Overtime Calculator
Calculate Austin hourly and weekly pay at the local $7.25/hr minimum.
Baltimore Minimum Wage & Overtime Calculator
Calculate Baltimore hourly and weekly pay at the local $15.00/hr minimum.
Boston Minimum Wage & Overtime Calculator
Calculate Boston pay at the $15.00/hr Massachusetts minimum wage
Chicago Minimum Wage & Overtime Calculator
Calculate Chicago hourly and weekly pay at the local minimum with overtime
Denver Minimum Wage & Overtime Calculator
Calculate Denver pay at the local $18.29/hr minimum with 1.5x overtime
Detroit Minimum Wage & Overtime Calculator
Calculate Detroit hourly and weekly pay at the local $10.10/hr minimum
Houston Minimum Wage & Overtime Calculator
Calculate Houston pay at the $7.25/hr minimum with 1.5x overtime.
Las Vegas Minimum Wage & Overtime Calculator
Calculate Las Vegas hourly and weekly pay at the local $12.00/hr minimum
Los Angeles Minimum Wage & Overtime Calculator — $17.28/hr
Calculate Los Angeles hourly and weekly pay at the local $17.28/hr minimum.
Louisville Minimum Wage & Overtime Calculator
Calculate Louisville hourly and weekly pay at the local $7.25/hr minimum.
Miami Minimum Wage & Overtime Calculator
Calculate Miami hourly and weekly pay at the local $13.00/hr minimum.
Minneapolis Minimum Wage & Overtime Calculator
Calculate Minneapolis hourly and weekly pay at the local $15.57/hr minimum.
Nashville Minimum Wage & Overtime Calculator
Calculate Nashville hourly and weekly pay at the $7.25/hr minimum.
New York City Minimum Wage & Overtime Calculator
Calculate New York City pay at the local $16.00/hr minimum wage.
Philadelphia Minimum Wage & Overtime Calculator
Calculate Philadelphia hourly and weekly pay at the local $7.25/hr minimum.
Phoenix Minimum Wage & Overtime Calculator
Calculate Phoenix hourly and weekly pay at the local $14.35/hr minimum
Portland Minimum Wage & Overtime Calculator
Compute Portland pay at the metro $15.45 minimum with 1.5x overtime
San Antonio Minimum Wage & Overtime Calculator
Calculate San Antonio hourly and weekly pay at the local $7.25/hr minimum.
San Diego Minimum Wage & Overtime Calculator
Calculate San Diego pay at the $17.25/hr minimum with CA overtime
San Francisco Minimum Wage & Overtime Calculator
Calculate San Francisco pay at the local $18.67/hr minimum with overtime
San Jose Minimum Wage & Overtime Calculator
Calculate San Jose pay at the $17.55/hr local minimum wage
Seattle Minimum Wage & Overtime Calculator
Calculate Seattle hourly and weekly pay at the local $19.97/hr minimum.
Tucson Minimum Wage & Overtime Calculator
Calculate Tucson hourly and weekly pay at the local minimum wage.
Austria USt Calculator (Umsatzsteuer) 2025
Add or extract Austria Umsatzsteuer at 20% — instant result in your browser.
Canada GST Calculator (Goods and Services Tax) 2025
Add or extract Canada Goods and Services Tax at 5% — instant result in your browser.
Czech Republic DPH Calculator (Daň z přidané hodnoty) 2025
Add or extract Czech Republic Daň z přidané hodnoty at 21% — instant result in your browser.
Denmark Merværdiafgift Calculator (Moms) 2025
Add or extract Denmark Moms at 25% — instant result in your browser.
Egypt VAT Calculator (Value Added Tax) 2025
Add or extract Egypt Value Added Tax at 14% — instant result in your browser.
Finland ALV Calculator (Arvonlisävero) 2025
Add or extract Finland Arvonlisävero at 25.5% — instant result in your browser.
Ghana VAT Calculator (Value Added Tax) 2025
Add or extract Ghana Value Added Tax at 15% — instant result in your browser.
Greece ΦΠΑ / FPA Calculator (Φόρος Προστιθέμενης Αξίας) 2025
Add or extract Greece Φόρος Προστιθέμενης Αξίας at 24% — instant result in your browser.
Hungary ÁFA Calculator (Általános Forgalmi Adó) 2025
Add or extract Hungary Általános Forgalmi Adó at 27% — instant result in your browser.
Portugal IVA Calculator (Imposto sobre o Valor Acrescentado) 2025
Add or extract Portugal Imposto sobre o Valor Acrescentado at 23% — instant result in your browser.
Romania TVA Calculator (Taxa pe Valoarea Adăugată) 2025
Add or extract Romania Taxa pe Valoarea Adăugată at 19% — instant result in your browser.
Turkey KDV Calculator (Katma Değer Vergisi) 2025
Add or extract Turkey Katma Değer Vergisi at 20% — instant result in your browser.
Bolivia Income Tax Calculator 2025 — 13% Flat Rate
Calculate your Bolivia take-home pay under the 13% flat income tax — monthly or annual, instant result in your browser.
Bosnia and Herzegovina Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Bosnia and Herzegovina take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Bulgaria Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Bulgaria take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Estonia Income Tax Calculator 2025 — 20% Flat Rate
Calculate your Estonia take-home pay under the 20% flat income tax — monthly or annual, instant result in your browser.
Hungary Income Tax Calculator 2025 — 15% Flat Rate
Calculate your Hungary take-home pay under the 15% flat income tax — monthly or annual, instant result in your browser.
Kazakhstan Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Kazakhstan take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Mongolia Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Mongolia take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
North Macedonia Income Tax Calculator 2025 — 10% Flat Rate
Calculate your North Macedonia take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Romania Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Romania take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Russia Income Tax Calculator 2025 — 13% Flat Rate
Calculate your Russia take-home pay under the 13% flat income tax — monthly or annual, instant result in your browser.
Turkmenistan Income Tax Calculator 2025 — 10% Flat Rate
Calculate your Turkmenistan take-home pay under the 10% flat income tax — monthly or annual, instant result in your browser.
Vikram Samvat Converter
Convert between Gregorian (CE) and Vikram Samvat (VS) years.
GST Inclusive / Exclusive Calculator
Add or remove GST at any rate — see net, GST and gross.
Reverse Sales Tax Calculator
Strip VAT, GST or sales tax out of a tax-inclusive price.
Paycheck Budget Split
Split your pay into needs, wants and savings.
Paycheck Splitter
Split every paycheck across needs, wants and savings — 50/30/20 or your own rules.
GST Calculator
Add or remove GST and see the net, tax and gross amounts instantly.
Salary to Hourly Converter
Turn any annual salary into hourly, daily, weekly and monthly pay — or work it backwards.
US Sales Tax Calculator
Enter an amount and a state to get the sales tax and total — with a 50-state rate reference.
Overtime Pay Calculator
Turn a regular rate, base hours and one or more overtime multipliers into a full gross-pay breakdown.
Australia GST Calculator
Add or remove 10% GST instantly — with a full AUD breakdown.
Belgium VAT Calculator (TVA / BTW)
Add or remove Belgian VAT at 21%, 12%, 6% or 0% — instant net and gross breakdown.
Germany VAT Calculator (Mehrwertsteuer)
Add or remove German MwSt at 19%, 7%, or 0% — instant net/gross breakdown.
Ireland VAT Calculator
Add or remove Irish VAT instantly — 23%, 13.5%, 9% and 4.8% rates covered.
Italy VAT (IVA) Calculator
Add or remove Italian IVA at 22%, 10%, 5% or 4% — instant breakdown in euros.
New Zealand GST Calculator
Add or remove 15% NZ GST instantly — with a full breakdown.
Norway VAT (MVA) Calculator
Add or remove Norwegian merverdiavgift at 25%, 15%, and 12% in seconds.
Poland VAT Calculator
Add or remove Polish VAT (PTU) instantly — 23%, 8%, and 5% rates.
Singapore GST Calculator
Add or remove 9% GST in seconds — net, GST amount, and gross in one view.
Philippines VAT Calculator
Add or remove Philippine 12% EVAT — instant peso breakdown for any transaction.
UAE VAT Calculator
Add or remove UAE VAT at 5% or 0% — instant AED net/gross breakdown.
India GST Calculator — All Slabs: 5%, 12%, 18%, 28% + CGST/SGST Split
Add or extract GST at any slab rate with a full CGST/SGST/IGST breakdown.
Arizona Sales Tax Calculator 2025 — 5.6% State TPT Rate + Local
Add or remove Arizona sales tax with the real 5.6% state rate and editable local rate — instant browser calculation.
California Sales Tax Calculator
Add or reverse California sales tax in seconds — state 7.25% + your local rate.
Canada Sales Tax Calculator (GST/HST/PST) by Province 2025
Instantly calculate GST, HST, PST and QST for every Canadian province and territory.
Florida Sales Tax Calculator 2025 — 6% State Rate + County Surtax
Add or remove Florida sales tax instantly — state base rate preset, editable county surtax, full breakdown.
France VAT (TVA) Calculator
Add or remove French TVA at 20%, 10%, 5.5% or 2.1% — instant net/gross breakdown.
Illinois Sales Tax Calculator
Add or back out Illinois sales tax — state 6.25% plus your local rate.
Mexico VAT (IVA) Calculator — 16%, 8% Border Zone, 0%
Add or remove Mexican IVA at 16%, 8% border-zone, or 0% — full MXN breakdown instantly.
Michigan Sales Tax Calculator 2025 — 6% Flat State Rate
Add or remove Michigan's flat 6% sales tax instantly — no local rate complications.
Missouri Sales Tax Calculator
Instantly calculate Missouri sales tax — add tax to a price or strip it from a total.
Netherlands VAT (BTW) Calculator
Add or remove Dutch BTW at 21%, 9% or 0% — instant net/gross breakdown.
New York Sales Tax Calculator
Calculate NY sales tax instantly — add tax to a price or strip it from a total.
Ohio Sales Tax Calculator
Instantly calculate Ohio sales tax — add tax to a price or back it out of a total.
Pennsylvania Sales Tax Calculator
Calculate PA sales tax — add it to a price or back it out from a total.
Saudi Arabia VAT Calculator
Add or remove 15% Saudi VAT instantly — net, VAT amount and gross in one click.
South Africa VAT Calculator
Add or remove 15% South African VAT instantly — net, VAT amount and gross in one click.
Spain VAT (IVA) Calculator
Add or remove Spanish IVA instantly — 21%, 10% and 4% rate bands covered.
Switzerland VAT (MWST) Calculator 2025 — 8.1%, 3.8%, 2.6%
Add or remove Swiss MWST at 8.1%, 3.8% or 2.6% — instant CHF breakdown in your browser.
Texas Sales Tax Calculator
Calculate Texas sales tax instantly — add tax to a price or back it out of a total.
Alabama Sales Tax Calculator 2025 — 4% State Rate + Local
Add or remove Alabama sales tax with the real 4% state rate and editable local rate — instant browser calculation.
Massachusetts Sales Tax Calculator
Add or reverse Massachusetts sales tax instantly — state 6.25% + optional local meals rate.
Colorado Sales Tax Calculator 2025 — 2.9% State Rate + Local
Add or remove Colorado sales tax with the real 2.9% state rate and editable local rate — instant browser calculation.
Georgia Sales Tax Calculator 2025 — 4% State + Local Rate
Add or remove Georgia sales tax instantly — state 4% base plus editable local rate.
Indiana Sales Tax Calculator 2025 — 7% State Rate, No Local Tax
Add or remove Indiana sales tax with the real 7% state rate — instant browser calculation, no local tax complications.
Kenya VAT Calculator 2025 — 16% Standard & 8% Petroleum Rate
Add or remove Kenya VAT at the correct rate band — instant KSh breakdown in your browser.
Louisiana Sales Tax Calculator 2025 — 4.45% State Rate + Local
Add or remove Louisiana sales tax with the real 4.45% state rate and editable parish/city rate — instant browser calculation.
New Jersey Sales Tax Calculator 2025 — 6.625% State Rate
Add or remove New Jersey sales tax instantly — state rate preset, editable local field, full breakdown.
Nigeria VAT Calculator — 7.5% Value Added Tax (2025)
Add or remove Nigeria VAT at 7.5% — instant breakdown in your browser.
North Carolina Sales Tax Calculator 2025 — 4.75% State Rate + Local
Add or remove NC sales tax instantly — state 4.75% base, editable county rate, full breakdown.
Sweden VAT (Moms) Calculator 2025 — 25%, 12%, 6%
Add or remove Swedish Moms instantly — all four rate bands, full SEK breakdown.
Washington Sales Tax Calculator
Add or reverse Washington sales tax — 6.5% state base rate + editable local rate.
Maryland Sales Tax Calculator 2025 — 6% Flat State Rate
Add or remove Maryland sales tax instantly — 6% statewide, no local add-ons.
Minnesota Sales Tax Calculator
Add or reverse Minnesota sales tax instantly — state 6.875% + your local rate.
South Carolina Sales Tax Calculator 2025 — 6% State Rate + Local
Add or remove SC sales tax instantly — state 6% base, editable county rate, full breakdown.
Tennessee Sales Tax Calculator 2025 — 7% State Rate + Local Rate
Add or remove Tennessee sales tax instantly — 7% state base preset, editable local rate, full breakdown.
Virginia Sales Tax Calculator 2025 — 4.3% State + Local Rate
Add or remove Virginia sales tax instantly — state 4.3% base plus editable local/regional rate.
Wisconsin Sales Tax Calculator 2025 — 5% State Rate + Local
Add or remove Wisconsin sales tax using the real 5% state rate and an editable county/city rate — instant browser calculation.
Alabama Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Alabama (federal) minimum wage, with overtime.
Arizona Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Arizona's $14.70/hr minimum — plus overtime.
Arkansas Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Arkansas's $11.00/hr minimum wage — with overtime.
California Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at California's $16.50/hr minimum — with overtime.
Florida Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Florida's $13/hr minimum — with overtime.
New York Minimum Wage Calculator
Compute gross pay at New York's $16.50/hr minimum wage — weekly, monthly, and annual.
Oregon Minimum Wage Calculator
Compute gross pay weekly, monthly and annually for all three Oregon wage tiers (July 2025) — with overtime.
Alaska Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Alaska's $11.91/hr rate — with overtime.
Colorado Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Colorado's $14.81/hr minimum wage, with overtime.
Connecticut Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at CT's $16.35/hr minimum wage — with overtime.
Hawaii Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at Hawaii's $16/hr minimum — with overtime.
Illinois Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at Illinois's $14/hr minimum — with overtime.
Maryland Minimum Wage Calculator
Compute gross pay at Maryland's $15.00/hr minimum — weekly, monthly, annual, with overtime.
Massachusetts Minimum Wage Calculator
Compute gross pay at the $15.00/hr MA minimum wage — weekly, monthly, annual, with overtime.
Michigan Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Michigan's $10.56/hr minimum wage, with overtime.
Missouri Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Missouri minimum wage, with overtime.
Montana Minimum Wage Calculator
Calculate gross pay at Montana's $10.55/hr minimum wage — weekly, monthly and annual.
New Jersey Minimum Wage Calculator
Instantly compute gross weekly, monthly, and annual pay at New Jersey's $15.49/hr minimum wage — with overtime.
New Mexico Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at the New Mexico minimum wage — with overtime.
Nebraska Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Nebraska minimum wage of $13.50/hr, with overtime.
Ohio Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Ohio's $10.70/hr minimum wage, with overtime.
Maine Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Maine's $14.65/hr rate — with overtime.
Minnesota Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Minnesota's $11.13/hr minimum wage, with overtime.
Nevada Minimum Wage Calculator
Compute weekly, monthly and annual gross pay at Nevada's $12/hr minimum — with overtime.
Alabama Property Tax Calculator
Estimate your Alabama annual and monthly property tax from your home value and the state average effective rate.
Arizona Property Tax Calculator 2024 — Estimate Your Annual and Monthly Bill
Enter your home value and get an instant Arizona property-tax estimate using the real 0.51% statewide average effective rate.
California Property Tax Calculator
Estimate your annual and monthly California property tax using the real statewide average effective rate.
Colorado Property Tax Calculator
Estimate your annual and monthly Colorado property tax from your home value.
Florida Property Tax Calculator
Estimate your annual and monthly Florida property tax from home value and effective rate.
Georgia Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Georgia (federal) minimum wage — overtime included.
Georgia Property Tax Calculator
Estimate your annual and monthly property tax bill for any Georgia county.
Iowa Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Iowa minimum wage, with overtime.
Kentucky Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Kentucky (federal) minimum wage, with overtime.
Pennsylvania Minimum Wage Calculator
Compute PA gross weekly, monthly and annual pay with overtime at the current state minimum wage.
Texas Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Texas minimum wage with overtime.
Louisiana Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Louisiana (federal) minimum wage, with overtime.
Connecticut Property Tax Calculator
Estimate your annual and monthly CT property tax — with county breakdowns.
Idaho Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Idaho minimum wage, with overtime.
Illinois Property Tax Calculator
Estimate your Illinois annual and monthly property tax from your home value and the state average effective rate.
Indiana Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Indiana minimum wage, with overtime.
Kansas Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Kansas minimum wage, with overtime.
Massachusetts Property Tax Calculator
Estimate your Massachusetts annual and monthly property tax from your home value and the state average effective rate.
Michigan Property Tax Calculator
Estimate your Michigan annual and monthly property tax from your home value and the state average effective rate.
Mississippi Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Mississippi (federal) minimum wage, with overtime.
Missouri Property Tax Calculator
Estimate your Missouri annual and monthly property tax from your home value and the state average effective rate.
Nevada Property Tax Calculator
Estimate your Nevada annual and monthly property tax from your home value and the state average effective rate.
New Hampshire Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the New Hampshire (federal) minimum wage, with overtime.
New York Property Tax Calculator
Estimate your New York annual and monthly property tax from your home value and the state average effective rate.
North Carolina Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the North Carolina minimum wage, with overtime.
North Dakota Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the North Dakota (federal) minimum wage, with overtime.
Ohio Property Tax Calculator
Estimate your Ohio annual and monthly property tax from your home value and the state average effective rate.
Oklahoma Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Oklahoma (federal) minimum wage, with overtime.
Oregon Property Tax Calculator
Estimate your Oregon annual and monthly property tax from your home value and the state average effective rate.
South Carolina Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the South Carolina (federal) minimum wage, with overtime.
South Dakota Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the South Dakota minimum wage, with overtime.
Tennessee Property Tax Calculator
Estimate your Tennessee annual and monthly property tax from your home value and the state average effective rate.
Texas Property Tax Calculator
Estimate your Texas annual and monthly property tax from your home value and the state average effective rate.
Wisconsin Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Wisconsin minimum wage, with overtime.
Wyoming Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Wyoming minimum wage, with overtime.
Rhode Island Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at RI's $16.00/hr minimum wage — with overtime.
Minnesota Property Tax Calculator
Estimate your Minnesota annual and monthly property tax from your home value and the state average effective rate.
New Jersey Property Tax Calculator
Estimate your NJ annual and monthly property tax from your home value and the state average effective rate.
North Carolina Property Tax Calculator
Estimate your North Carolina annual and monthly property tax from your home value and the state average effective rate.
Pennsylvania Property Tax Calculator
Estimate your Pennsylvania annual and monthly property tax from your home value and the state average effective rate.
Tennessee Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Tennessee (federal) minimum wage, with overtime.
Utah Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Utah minimum wage, with overtime.
Virginia Property Tax Calculator
Estimate your Virginia annual and monthly property tax from your home value and the locality effective rate.
Washington State Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Washington's $16.66/hr minimum wage — with overtime.
Wisconsin Property Tax Calculator
Estimate your Wisconsin annual and monthly property tax from your home value and the state average effective rate.
Indiana Property Tax Calculator
Estimate your Indiana annual and monthly property tax from your home value and the state average effective rate.
Vermont Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the Vermont minimum wage, with overtime at 1.5x.
Washington Property Tax Calculator
Estimate your Washington annual and monthly property tax from your home value and the state average effective rate.
Virginia Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Virginia's $12.41/hr minimum wage, with overtime.
West Virginia Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at the West Virginia minimum wage of $8.75/hr, with overtime.
Kinematics Calculator (SUVAT + Projectile)
Solve any SUVAT equation or projectile problem — pick the unknown and get full working.
Delaware Minimum Wage Calculator
Compute gross weekly, monthly and annual pay at Delaware's $15.00/hr minimum wage with overtime.
Activation Energy Calculator
Arrhenius equation, two-point Eₐ, first-order half-life and Eyring–Polanyi in one tool.
Boiling Point Elevation Calculator
Calculate ΔTb = i · Kb · m — solve for elevation, Kb, molality or Van't Hoff factor.
Elevation Grade Calculator
Convert between slope grade %, angle, rise, run and slope distance instantly.
Medical & Clinical
APGAR Score Calculator
Neonatal assessment at 1, 5, and 10 minutes after birth
Blood Alcohol Concentration Estimator (Widmark)
Estimate BAC from drinks consumed, weight, and time elapsed
BUN:Creatinine Ratio Calculator
Classify azotaemia as pre-renal, intrinsic renal, or post-renal
Corrected Gestational Age for Premature Infants
Compute developmental corrected age from birthdate and gestation
Corrected Calcium for Albumin
Adjust serum calcium when albumin is abnormal
Paediatric GFR Estimator (Schwartz Formula)
Estimate GFR in children from height and serum creatinine
Creatinine Clearance (Cockcroft-Gault)
Estimate kidney function for drug dosing adjustments
Cystatin C-Based eGFR Calculator (CKD-EPI Cys)
GFR estimate using cystatin C alone or combined with creatinine
Creatinine Unit Converter (mg/dL to umol/L)
Convert serum creatinine between US and SI units
Drug Dose by BSA Calculator
Body surface area-based dosing for chemotherapy and specialty drugs
eGFR Calculator (CKD-EPI & MDRD)
Estimate GFR and CKD stage with two validated equations
GFR-Based CKD Staging Tool
Map any eGFR value to its KDIGO CKD G-stage
Mean Arterial Pressure (MAP) Calculator
Calculate MAP from systolic and diastolic blood pressure
TBSA Burn Calculator (Rule of Nines & Lund-Browder)
Estimate total body surface area burned for resuscitation.
Protein:Creatinine Ratio & Albumin:Creatinine Ratio Calculator
Estimate 24-hour proteinuria from a spot urine sample
Urine Anion Gap Calculator
Classify metabolic acidosis as GI versus renal bicarbonate loss
Blood Alcohol Content (BAC) Calculator
Estimate your BAC with the Widmark formula — never use it to decide to drive.
Metabolic Age Calculator
Estimate your metabolic age from your BMR.
Anion Gap Calculator
Instantly compute anion gap, albumin-corrected AG, delta ratio and osmolar gap.
APGAR Score Calculator
Assess a newborn's health at birth with the standard five-criterion APGAR scale.
Body Surface Area (BSA) Calculator
Calculate BSA using Mosteller, DuBois, Haycock and three more formulae — instantly in your browser.
Cat Years Calculator
Find out how old your cat is in human years — with life-stage guidance.
Corrected Calcium Calculator
Adjust serum calcium for low or high albumin using the Payne formula.
Creatinine Clearance Calculator (Cockcroft-Gault)
Estimate kidney function for drug dosing using the Cockcroft-Gault equation.
eGFR Calculator (CKD-EPI 2021)
Estimate kidney function from serum creatinine using the latest race-free equation.
Gestational Age Calculator
Find out exactly how far along you are — in weeks and days.
eGFR Calculator (CKD-EPI 2021)
Estimate kidney function using the latest race-free CKD-EPI 2021 equation.
MAP Calculator (Mean Arterial Pressure)
Instantly compute Mean Arterial Pressure from systolic and diastolic readings.
Mean Arterial Pressure (MAP) Calculator
Instantly compute MAP from systolic and diastolic blood pressure readings.
Pet Age Calculator
Convert your pet's age to a human-equivalent age using real veterinary science.
QTc Interval Calculator
Correct the QT interval for heart rate using Bazett, Fridericia, Framingham and Hodges formulas.
Dog Years Calculator
Convert your dog's age to human years with size-aware milestones and life-stage analysis.
Caffeine Half-Life Calculator
See exactly how much caffeine is still in your system and when you can safely sleep.
Glycemic Load Calculator
Calculate the glycemic load of any meal from a database of 60+ foods.
Sugar Intake Calculator
Track your daily sugar consumption against WHO, AHA and NHS limits.
Fiber Intake Calculator
Find your daily fiber target and track it food by food.
Sodium Intake Calculator
Track your daily sodium and salt intake against WHO, AHA and NHS limits.
Standard Drink Calculator
Convert any drink into standard units for US, UK, Australia and Canada.
Health & Fitness
BMI / BMR / TDEE Calculator
Body mass index, basal metabolic rate and daily calorie needs in one tool.
Pregnancy Due Date Calculator
Estimated due date, gestational age and trimester from your last period.
Aquarium Protein Skimmer Sizing Calculator
Match protein skimmer rated volume to your actual bioload
Beer Calories & Carbs Calculator
Estimate calories and carbohydrates per serving from OG and FG
Bellows & Extension Tube Exposure Calculator
Calculate exposure increase and magnification for bellows and tubes
Close-Up Lens Diopter Calculator
Find magnification and focus distance for close-up filters
Macro Lens Working Distance Calculator
Calculate working distance from front element to subject at any magnification
Macro Focus Stacking Step Calculator
Calculate focus step distance for complete depth-of-field coverage in macro stacks
Pet Body Condition Score Calculator
Estimate your dog or cat's body condition score from a quick check
Pet Gestation & Due Date Calculator
Calculate expected due date for dogs, cats, rabbits, and guinea pigs
Beer-Lambert Protein Concentration Calculator
Quantify protein concentration from absorbance and an extinction coefficient
Adult BMI Calculator & WHO Classification
BMI from height and weight with underweight to obese classification
Obesity Class & Drug Dosing Weight Selector
Pick the right dosing weight (ABW, IBW, AdjBW, LBW) by drug class
Pediatric BMI Percentile Calculator (CDC)
Age- and sex-adjusted BMI percentile for children 2-20
Lean Body Weight Calculator (Janmahasatian)
LBW for drug dosing in obese and normal-weight patients
Cardiovascular Lipid Risk Calculator (Framingham)
10-year CVD risk from lipid panel, age, sex, BP, and smoking
BCA / Bradford Protein Assay Standard Curve Calculator
Fit a protein standard curve and read off unknown concentrations
Protein Yield & Recovery Calculator
Track total protein, activity, and purification fold across fractions
Oral Rehydration Solution Dosing Calculator
Calculate ORS volume for mild and moderate dehydration
BMR Calculator
Your Basal Metabolic Rate with the Mifflin-St Jeor equation.
TDEE Calculator
Total Daily Energy Expenditure from BMR and activity level.
Body Fat Calculator
Estimate body fat percentage with the US Navy method.
Ideal Weight Calculator
Ideal body weight from four classic formulas.
Lean Body Mass Calculator
Lean mass and fat mass from the Boer formula.
Calorie Deficit Calculator
Find your daily calorie target for steady, safe weight loss.
Macro Calculator
Split your daily calories into protein, carbs and fat in grams.
Water Intake Calculator
Estimate how much water to drink each day for your body and activity.
Running Pace Calculator
Work out pace, finish time or distance for any run.
One Rep Max Calculator
Estimate your 1RM and training weights from a set you can do.
Sleep Cycle Calculator
Find the best bedtime or wake-up time around 90-minute cycles.
Joules to Calories Converter
Convert J to cal instantly — 1 cal = 4.184 J. Free, browser-only tool.
Pregnancy Week Tracker
See how many weeks pregnant you are, your trimester and your due date.
Calorie Burn by Activity Calculator
Estimate calories burned for any activity using MET values.
BMI Prime Calculator
Express your BMI as a ratio to the healthy-weight ceiling of 25.
Waist-to-Height Ratio Calculator
Check if your waist is less than half your height — a simple health screen.
VO2 Max Calculator
Estimate your VO2 max from resting HR, a Cooper run or a Rockport walk.
Waist-to-Hip Ratio Calculator
Divide waist by hip and see your WHO health-risk band.
Protein Intake Calculator
How much protein per day for maintenance, muscle gain or fat loss.
Max Heart Rate Calculator
Your maximum heart rate plus five training zones, with Karvonen support.
Running Pace Converter
Convert between min/km, min/mile, km/h and mph instantly.
Pregnancy Weight Gain Calculator
Check your pregnancy weight gain against IOM guidelines by week.
Calories In vs Out Calculator
See your daily calorie balance and projected weight change.
Joules to Food Calories Converter
Convert joules to nutrition-label Calories (kcal) and back.
Calories to Joules Converter
Convert small (gram) calories to joules and back, exactly.
Target Heart Rate Zone Calculator
Training zones by Karvonen or percentage of max HR.
Calories Per Meal Planner
Split your daily calorie target across meals.
Steps to Calories Calculator
Convert your step count into calories burned.
Pregnancy Trimester Calculator
Find your trimesters, due date and gestational age.
BMI-for-Age Percentile Calculator
Child & teen BMI percentile using CDC growth charts.
Marathon Time Predictor
Predict your marathon finish from a recent race using the Riegel formula.
VDOT Running Calculator
Find your VDOT fitness score from any race time (Daniels–Gilbert model).
Swim Pace Calculator
Work out your pace per 100 m or 100 yd and average swim speed.
Calories to Kilojoules Converter
Convert food calories (kcal) to kilojoules, both directions.
Kilojoules to Calories Converter
Convert kilojoules to food calories (kcal), both directions.
Heart Rate Recovery Calculator
How fast your pulse drops after exercise.
Pace Per Kilometer Calculator
Turn distance and time into min/km, min/mile and km/h.
Daily Calorie Cycling Calculator
Split your weekly calories into high and low days.
Hydration Reminder Calculator
Your daily water target and a drink-every-X-minutes schedule.
Workout Program Builder
Build a weekly training split, track sets and reps, and export a printable PDF.
Macro Meal Planner
Plan a day of meals, hit your protein, carb and fat targets, export the plan.
Workout Log
Track sets, reps and weight per session — with history and personal-best highlights.
BMR & TDEE Calculator
Find your BMR, daily calorie burn and goal calorie targets in seconds.
Calorie & Macro Daily Tracker
Log foods against calorie and macro targets with live progress rings.
Body Fat Calculator (US Navy Method)
Estimate body fat % from a tape measure using the US Navy formula.
Sleep Cycle Calculator Pro
Bedtime, wake-up and nap times tuned to your own 90-minute cycles.
Heart Rate Zone Calculator
Turn your age and resting pulse into five training zones with exact BPM ranges.
One Rep Max Calculator (Pro)
Estimate your 1RM from seven formulas, with a full training-percentage table in kg and lb.
Water Intake Calculator (Advanced)
Personalised daily water target from weight, age, activity and climate.
BMI Calculator with Healthy Weight Range
Body mass index, your category, and the healthy weight range for your height.
Running Pace Calculator Pro: Pace, Time, Distance + Splits
Enter any two of pace, time and distance — get the third, plus splits and race predictions.
Sourdough Hydration & Baker's Percentage Calculator
Find your dough hydration and every baker's % in one click.
Pace Per Mile Calculator
Find your pace, finish time or distance — in minutes per mile.
Rowing Split Calculator
Convert your split to watts, calories and total time — or find the split you need to hit a goal time.
Steps to Miles Calculator
Convert any step count to miles and kilometres instantly.
Calories Burned Cycling Calculator
Find out exactly how many calories you burn on every ride.
Calories Burned Swimming Calculator
Find out exactly how many calories you burn for every stroke and session.
FFMI Calculator
Calculate your Fat-Free Mass Index and see how your muscularity compares.
Heart Rate Reserve Calculator
Find your true Karvonen training zones using the HRR method.
Marathon Pace Predictor
Goal time, training zones, negative splits and 5-km split cards — all from one number.
Plate Loading Calculator
Instantly know which plates to load on each side of the bar — kg and lb.
Running Cadence Calculator
Find your ideal steps per minute from speed and stride length.
Steps to Calories Calculator
Convert any step count to calories burned — with distance, pace, fat burned, and daily projections.
Wilks Calculator
Compare your powerlifting total across any bodyweight class.
Calories Burned Running Calculator
Find out exactly how many calories your run burns — by speed, weight and distance or time.
DPI / Dots Calculator
Calculate PPI for screens and DPI for print — find the right resolution in seconds.
Beep Test Calculator
Find your VO2 max and fitness rating from your 20m shuttle run level and shuttle.
Brzycki 1RM Calculator
Estimate your one-rep max from any rep-weight set using the Brzycki formula.
Cooper Test Calculator
Estimate VO2max from your 12-minute run — with age and sex fitness norms.
Epley 1RM Calculator
Estimate your one-rep max from any submaximal lift in seconds.
Treadmill Pace Converter
Convert treadmill speed to running pace, finish times and calorie burn instantly.
Calorie Cycling Calculator
Plan high, medium, low and rest-day calories around your training week.
RPE Load Calculator
Translate Rate of Perceived Exertion to exact training loads using the Tuchscherer RTS chart.
Waist-to-Height Ratio Calculator
Check your central obesity risk with the simple keep-your-waist-to-half-your-height rule.
Waist-to-Hip Ratio Calculator
Calculate your WHR, see your WHO risk band, and solve for the waist size you need.
Wendler 5/3/1 Calculator
Generate your full 4-week 5/3/1 cycle — sets, weights, AMRAP targets and progression.
Grade Adjusted Pace Calculator (GAP)
Find your flat-equivalent running pace on any hill using the Minetti metabolic model.
Reverse Diet Calculator
Ramp calories back to maintenance with minimal fat gain.
Running Economy Calculator
Calculate your oxygen cost per km, energy cost (Cr) and running efficiency from a sub-maximal VO2 test.
TDEE Calculator — Katch–McArdle & Cunningham
The most accurate lean-mass TDEE: Katch–McArdle + Cunningham, with solve-for-body-fat mode.
Pregnancy Due Date Calculator
Find your estimated due date using LMP, conception, IVF transfer, or ultrasound dating.
Ovulation Calculator
Find your fertile window and estimated ovulation date for the next 1–6 cycles.
Pregnancy Week Calculator
Find out exactly which week of pregnancy you are in and see what comes next.
Running Pace to Speed Converter (Tempo to mph / km/h)
Convert any running pace to mph, km/h and m/s — plus instant race finish times.
Army Body Fat Calculator
Estimate body fat with the official U.S. Army AR 600-9 circumference formula and check your Army standard.
Fat-Burning Zone Calculator
Find the exact heart-rate range where your body burns the most fat per minute.
Hydration During Exercise Calculator
Know exactly how much to drink before, during and after your workout.
Protein Per Meal Calculator
Find out exactly how much protein to eat at each meal for your body weight and goal.
Heart Rate Zone Calculator
Find your 5 training zones using Karvonen or % Max HR.
Target Heart Rate Calculator
Find your ideal training heart-rate zone for any fitness goal.
VO2max From Race Time Calculator
Derive your VDOT and five training pace zones from any recent race result.
Calories in Recipe Calculator
Total calories, macros and per-serving breakdown for any home-cooked dish.
Chemistry
Aquarium CO2 / pH / KH Calculator
Calculate dissolved CO2 from measured pH and carbonate hardness
D&D Polymorph Stat Block Reference
Quick lookup of CR-appropriate polymorph target stat blocks
Garden Soil pH Amendment Calculator
Calculate lime or sulfur needed to adjust soil pH to target
Mash pH Estimator
Estimate mash pH from grain bill, water profile, and acid additions
Sour Beer Lactic Acid Titration Calculator
Estimate lactic acid additions to reach a target pH in finished sour beer
Wort Dilution & Boil-Off Calculator
Calculate post-dilution or post-boil gravity from volume changes.
Economizer Changeover Temperature & Enthalpy Calculator
Find the dry-bulb and differential-enthalpy changeover points for an air-side economizer
Dilution Calculator (C₁V₁ = C₂V₂)
Calculate stock solution volumes for any target concentration
Dilution Factor & Back-Calculation Tool
Find dilution factor and original concentration from a diluted sample
Freezing Point Depression Calculator
Calculate delta Tf and osmolality of solutions for formulation
Henderson-Hasselbalch Buffer pH Calculator
Calculate buffer pH from pKa and acid/base concentrations
Air Enthalpy Calculator (HVAC)
Moist-air enthalpy in BTU/lb from dry-bulb and wet-bulb or relative humidity
Antibody Dilution Calculator for IHC / ICC
Calculate working dilution volumes for immunohistochemistry antibody solutions
Knots / MPH / km/h / m/s Speed Converter
Convert between nautical, imperial, and metric speed units instantly
Ligation Molar Ratio Calculator (Insert:Vector)
Calculate insert mass for a 3:1 or custom molar ratio in cloning
MIC Dilution Series Planner
Plan two-fold dilution series for minimum inhibitory concentration testing
Osmolarity of Solution Calculator
Calculate solution osmolarity from solute concentrations and dissociation
ppm / ppb / % Concentration Converter
Convert between ppm, ppb, mg/L, g/L, and % for solutions
Reagent Preparation & Dilution Planner
Plan a serial dilution series with per-tube transfer and diluent volumes
Serial Dilution Calculator
Calculate concentrations across every step of a serial dilution series
Serum Osmolality & Osmol Gap Calculator
Estimate osmolality and osmol gap to screen for toxic alcohols
Acid-Base Titration Calculator
Calculate titre volume, equivalence point, and concentration
Token Dilution & Fully Diluted Valuation Calculator
Calculate FDV, circulating market cap, and dilution from future unlocks
Urine Specific Gravity to Osmolality Converter
Convert urine SG to approximate osmolality for hydration assessment
Miles per Hour to Kilometres per Hour Converter
Convert mph to km/h instantly — 1 mph = 1.609344 km/h. Free, browser-only tool.
Miles per Hour to Knots Converter
Convert mph to kn instantly — 1 mph = 0.868976 kn. Free, browser-only tool.
Percent Yield Calculator
Percent yield from actual and theoretical yield — or solve either.
Ideal Gas Law Calculator
Solve PV = nRT for pressure, volume, moles or temperature — with units and steps.
Molarity Calculator
Solve for molarity, moles, mass or volume — with grams to moles built in.
pH Calculator
Convert between pH, pOH, [H⁺] and [OH⁻], and get pH from strong acid or base concentration.
Dilution Calculator (C1V1 = C2V2)
Solve the dilution equation for any concentration or volume, with units.
Molar Mass Calculator
Molar mass of any chemical formula, with per-element breakdown.
Cocktail Dilution Calculator
Know exactly how much ice water enters your drink — and where your ABV lands.
Titration Calculator
Find analyte concentration, titrant volume or equivalence point from any three knowns.
Ideal Gas Law Calculator (PV = nRT)
Solve for pressure, volume, moles or temperature — with full unit conversion.
Combined Gas Law Calculator
Solve P₁V₁/T₁ = P₂V₂/T₂ — plus Boyle, Charles, Gay-Lussac and the Ideal Gas Law.
Empirical Formula Calculator
Find the empirical and molecular formula from mass percentages or masses.
Enthalpy Calculator
Hess's Law, Gibbs ΔG, bond enthalpies, Kirchhoff, calorimetry — all in one tool.
Entropy & Gibbs Free Energy Calculator
Calculate ΔS, ΔG, Boltzmann entropy and more — six thermodynamic laws in one tool.
Equilibrium Constant Calculator
Kc, ICE tables, van't Hoff and Q vs Kc — all in one tool.
Gibbs Free Energy Calculator
Calculate ΔG, ΔH, ΔS, equilibrium constants and Nernst cell potentials instantly.
Molality Calculator
Calculate molality, solute mass, solvent mass, or molar mass — with full working shown.
pH and pOH Calculator
Convert between pH, pOH, and ion concentrations — with Henderson–Hasselbalch, buffer capacity, and dilution.
PPM Calculator
Convert ppm to molarity, run Beer-Lambert, dilute to a target concentration — all in one place.
Rate of Reaction Calculator
Arrhenius, rate laws, half-lives, activation energy — six chemistry modes in one tool.
Stoichiometry Calculator
Molar mass, limiting reagent, percent yield, molarity and ideal gas law — all in one place.
Atom Economy Calculator
Atom economy, E-factor, PMI, RME and mass balance — green chemistry metrics in one tool.
Beer-Lambert Law Calculator
Solve for absorbance, concentration, molar absorptivity, or path length instantly.
Boyle's Law Calculator
Solve P₁V₁ = P₂V₂ instantly — find any missing pressure or volume.
Charles's Law Calculator
Solve V1/T1 = V2/T2 instantly — find any gas volume or temperature at constant pressure.
Dalton's Law of Partial Pressures Calculator
Compute total pressure, partial pressures and mole fractions for any gas mixture.
Freezing-Point Depression Calculator
Calculate ΔTf, molality, Kf, or the van t Hoff factor — with full step-by-step working.
Gay-Lussac's Law Calculator
Solve P1/T1 = P2/T2 instantly — pressure, temperature, or both.
Graham's Law of Effusion Calculator
Compare gas effusion rates using r₁/r₂ = √(M₂/M₁). Solve for rate ratio, individual rate, or unknown molar mass.
Henderson-Hasselbalch Calculator
Solve pH, pKa, [A⁻] or [HA] with full step-by-step working.
Limiting Reagent Calculator
Find the limiting reagent, theoretical yield, excess amounts and percent yield instantly.
Mole Fraction Calculator
Find mole fractions, mole percentages and partial pressures for any gas or liquid mixture.
Normality Calculator
Calculate normality, equivalent weight, molarity conversions, dilutions and titration endpoints.
Osmotic Pressure Calculator (van 't Hoff: π = iMRT)
Solve for osmotic pressure, concentration, temperature or the van 't Hoff factor — with full unit support.
Theoretical Yield Calculator
Find theoretical yield, percent yield, or actual yield — with full stoichiometric working.
Nernst Equation Calculator
Calculate cell potential, standard E°, electrons transferred, reaction quotient or temperature — with full step-by-step working.
Percent Composition Calculator
Find the mass percent of every element in any chemical formula instantly.
Scoville Dilution Calculator
Calculate how much diluent to add to hit your target heat level.
Physics
Crossbow Kinetic Energy Calculator
Calculate crossbow bolt kinetic energy and momentum for ethical hunting.
HVAC Duct Sizing Calculator (Equal-Friction Method)
Size round and rectangular ducts from target friction rate and CFM using ASHRAE equal-friction
Newtonian Telescope Collimation Offset Calculator
Calculate secondary mirror offset for any Newtonian reflector
Concrete Pump Friction Loss Calculator
Estimate line pressure loss for concrete pump hose and pipe runs
HVAC Duct Friction Loss Calculator
Calculate friction loss in inches WC per 100 ft for round sheet-metal duct
One-Compartment PK Parameter Calculator
Estimate Cmax, Cmin, AUC, t½, and Vd from two drug levels
Pipe Thermal Expansion Calculator
Calculate thermal growth for copper, steel, PEX, and CPVC pipe over a temperature range
Momentum Calculator
Momentum p = m × v and impulse J = F × t, instantly.
Gravitational Force Calculator
Newton's law of gravitation: F = G·m₁·m₂ / r².
Newtons to Pounds-force Converter
Convert newtons to pounds-force instantly — 1 lbf = 4.4482216 N. Free, browser-only.
Escape Velocity Calculator
Work out the speed needed to escape any body's gravity.
Orbital Period Calculator
Compute how long one orbit takes with Kepler's third law.
Celsius to Newton Scale Converter
Convert °C to the historic Newton temperature scale, both ways.
Kinetic Energy Calculator
Solve KE = ½ m v² for energy, mass, or velocity — with full working shown.
Power-to-Weight Ratio Calculator
Compare two vehicles' power-to-weight ratios in W/kg, kW/t and hp/t.
Projectile Motion Calculator
Launch speed and angle to range, max height, flight time — with trajectory chart.
Doppler Shift Calculator
Calculate observed frequency, redshift and wavelength change for sound or light.
Lens Equation Calculator
Solve the thin lens equation for f, do or di — plus magnification, optical power and a live ray diagram.
Pressure at Depth Calculator
Calculate hydrostatic pressure at any depth — gauge and absolute, any fluid.
Reynolds Number Calculator
Predict laminar, transitional or turbulent flow — solve for Re, velocity, length or viscosity.
Terminal Velocity Calculator
Calculate the terminal velocity of any falling object using real aerodynamics.
Buoyancy Calculator
Compute buoyant force, fluid density, or submerged volume using Archimedes' principle.
Gas Density Calculator
Calculate gas density from pressure, temperature and molar mass — or solve for P or T.
Pendulum Period Calculator
Calculate period, length or gravity for a simple pendulum using T = 2π√(L/g).
Snell's Law Calculator
Compute refracted angle, incident angle, or refractive index — with critical-angle and Fresnel reflectance.
Specific Heat Calculator
Calculate heat energy, mass, specific heat capacity or temperature change using Q = m·c·ΔT.
Spring Constant Calculator
Hooke's Law — solve for k, force, or displacement with elastic PE and natural frequency.
Thermal Expansion Calculator
Calculate linear, area and volumetric expansion for 30 materials using ΔL = α · L₀ · ΔT
Angular Velocity Calculator
Calculate angular velocity, centripetal acceleration, tangential speed and more — with unit conversions.
Free Fall Calculator
Solve distance, time, velocity or g for any free-fall problem — Earth, Moon, Mars and beyond.
Friction Calculator
Compute friction forces, normal forces, slip angles and incline acceleration — with full working shown.
Power Physics Calculator
Solve P = W/t, P = Fv, P = τω, P = VI, P = I²R, hydraulic, rotational KE and more — with full working shown.
Banking Angle Calculator
Find the ideal banking angle, speed, or curve radius for any banked turn.
Coulomb's Law Calculator
Calculate electrostatic force between two point charges — solve for F, q₁, q₂, or r.
de Broglie Wavelength Calculator
Calculate the quantum wavelength of any moving particle — electrons, protons, neutrons, or custom masses.
Frequency and Period Calculator
Instantly convert between frequency f, period T, and angular frequency omega — with unit-aware results across Hz to THz.
Gravitational Force Calculator
Newton's universal gravitation: F = G * m1 * m2 / r2. Solve for any variable.
Impulse Calculator
Solve J = F·Δt or J = m·v_f − m·v_i with step-by-step working.
Kinetic Friction Calculator
Calculate friction force, stopping distance, incline dynamics and work done by friction.
Moment of Inertia Calculator
Compute I for 11 shapes, solve rotational KE and angular momentum — with the parallel axis theorem built in.
Newton's Second Law Calculator
F = ma — solve for force, mass, acceleration plus impulse, work, friction, circular motion, and inclined planes.
Orbital Velocity Calculator
Find the speed needed for a circular orbit around any body — with escape velocity, period and geostationary orbit.
Torque Physics Calculator
Solve torque, angular acceleration, rotational power, work, and lever balance — with full working shown.
Work & Energy Calculator
Solve work, KE, PE, power, momentum, impulse, collisions and centripetal force — with full working shown.
Centripetal Force Calculator
Solve F = m·v²/r instantly — force, mass, velocity, or radius.
Gravitational Potential Energy Calculator
Calculate PE = mgh instantly — solve for energy, mass, height, or g.
Hooke's Law Calculator
Solve F=kx, elastic PE, series/parallel springs and SHM oscillation — with full working.
Projectile Range Calculator
R = v₀²·sin(2θ)/g — range, height, flight time, impact speed.
Wave Speed Calculator
v = f × λ — solve for wave speed, frequency, wavelength, or period.
Electronics
Audio Transformer Turns Ratio & Impedance
Calculate turns ratio and impedance transformation for audio transformers
Battery Backup (UPS) Load & Runtime Calculator
Calculate UPS kVA, battery amp-hours, and backup runtime for critical loads.
Battery Bank Sizing Calculator (Off-Grid Solar)
Size a 12/24/48 V battery bank by daily load, days of autonomy, and depth of discharge.
RC Circuit Charge / Discharge Time Calculator
Calculate RC time constant, voltage at any time, and 5 tau full-charge time
Control Transformer Sizing Calculator
Size a control power transformer for a control panel load list with inrush allowance.
dB to Voltage Gain Converter
Convert between dB values and voltage gain/attenuation ratios instantly.
Drone Battery Cell Count & Voltage Calculator
Understand LiPo cell count, nominal, and charged voltage
kVA to Amps Converter
Convert kilovolt-amperes to amps for single-phase, split-phase, and three-phase systems
LED Retrofit Savings Calculator
Calculate annual energy and cost savings when replacing fluorescent or HID fixtures with LED
LiPo Battery Capacity & Flight Time Calculator
Calculate RC/drone flight time from battery capacity and current draw
Power Factor Correction Capacitor Calculator
Size a capacitor bank to correct power factor from a measured PF to a target PF
PV String Voc Temperature Correction Calculator
Correct PV module open-circuit voltage for minimum site temperature per NEC 690.7
Sealed Subwoofer Box Volume Calculator
Size a sealed sub box from Thiele-Small parameters and read its Qtc and Fc.
Transformer kVA Calculator
Determine required transformer kVA from load amps, voltage, and phase
Wire Gauge Selector
Choose the correct AWG or kcmil conductor for any load current with ampacity derating
Three-Phase Voltage Imbalance Calculator
Calculate percent voltage unbalance per NEMA MG1 and flag motor derating requirements.
Battery Charger Sizing Calculator
Size a 12/24/48 V battery charger from bank Ah capacity and recharge time
EU Battery Regulation Compliance Checker
Check battery product compliance with EU Regulation 2023/1542
Battery State of Charge (SoC) Estimator
Estimate lead-acid or lithium battery SoC from resting voltage or Peukert-corrected Ah.
Chilled Water Pipe Sizing Calculator
Size chilled-water piping by GPM and ASHRAE velocity limits, with head loss
CTWD / Contact-Tip-to-Work Distance Calculator
Find voltage drop and burnback risk from CTWD change in MIG welding
Deck Ledger Bolt Calculator
Calculate ledger-to-house bolt count and spacing from deck size
Emergency Lighting Battery Runtime Calculator
Verify emergency lighting fixture battery runtime meets NFPA 101 90-minute minimum requirement.
HAS-BLED Bleeding Risk Score
Estimate major bleeding risk before anticoagulation in AF
High-Leg Delta Voltage Calculator
Find the wild-leg voltage on a 120/240 V delta service and confirm phase B marking
LED Lighting Savings Calculator
Calculate energy savings and payback from switching to LED bulbs
Medium-Voltage Cable Sizing Calculator (5–35 kV)
Size MV feeder cables for shielded 5 kV–35 kV systems with ampacity and voltage-drop check.
RE100 Renewable Energy Pledge Progress Calculator
Track annual renewable energy percentage progress toward a 100% RE target
Solar + Battery Hybrid System Sizing Calculator
Jointly size solar array, battery bank and hybrid inverter for a self-consumption system.
Transformer Efficiency & No-Load Loss Calculator
Efficiency at partial load and annual no-load energy from core-loss spec
Underground Conduit Burial Depth Checker (NEC 300.5)
Verify NEC Table 300.5 minimum burial depth for conduit and direct-buried cable by method.
Resistor Color Code Calculator
Decode 4-band resistor colour bands to ohms.
Decibel (dB) Calculator
Convert a power or amplitude ratio to decibels.
Ohm's Law Calculator
Enter any two of V, I, R or P — get the other two with the formula wheel.
Resistor Color Code Calculator
Decode 4, 5 and 6-band resistors — or work backwards from a value to the colours.
Battery Life Calculator
Capacity, load and efficiency → exact runtime hours, minutes and a discharge curve.
Capacitor Code Calculator
3-digit EIA code to capacitance — and back. With tolerance band and voltage rating.
LED Resistor Calculator
Series resistor, nearest E12/E24 value and power rating — instantly.
Voltage Divider Calculator
Solve for Vout, Vin, R1 or R2 — with current, power and full working.
Wire Gauge (AWG) Calculator
AWG to diameter, ampacity with derating, and voltage drop for any run length.
555 Timer Calculator
Astable frequency, duty cycle and monostable pulse width — with full working.
LC Resonant Frequency Calculator
Find the resonant frequency, inductance, or capacitance of any LC tank circuit instantly.
Op-Amp Gain Calculator
Instantly calculate voltage gain, bandwidth and resistor values for any op-amp configuration.
PC Power Supply Calculator
Find the right PSU wattage for your build — CPU, GPU, storage and all.
Voltage Drop Calculator
Calculate voltage drop for any cable run — or find the minimum wire size for a target drop limit.
Antenna Length Calculator
Calculate the exact physical length for any antenna type from frequency — or find the resonant frequency from a known length.
Battery Runtime Calculator
Peukert-corrected runtime, required capacity, and max load for any battery pack.
Capacitor Charge Calculator
Calculate charge, voltage, capacitance, energy stored and dynamic charge/discharge voltage in an RC circuit.
Capacitor Parallel & Series Calculator
Instantly find the total capacitance of any combination of capacitors in parallel or series.
Decibel Distance Calculator
How loud is a sound at a different distance? Instant inverse-square-law answer.
Generator Sizing Calculator
Calculate the exact kVA rating you need — with motor surge, altitude and temperature derating.
RC Time Constant Calculator
Calculate τ = R × C, cutoff frequency, and capacitor voltage at any time.
Resistor Parallel Calculator
Equivalent resistance, conductance breakdown and solve-for-missing-R — all in one tool.
Transformer Turns Ratio Calculator
Compute secondary voltage, current, reflected impedance and winding counts for any transformer.
UPS Runtime Calculator
How long will your UPS last? Peukert-corrected battery runtime with real efficiency losses.
Resistor Series Calculator
Total resistance, current, voltage drops and power for any series resistor network.
Solar Battery Bank Calculator
Size a solar battery bank with the correct Ah formula — autonomy, DoD, efficiency, cell config.
Dipole Antenna Calculator
Instantly calculate half-wave dipole, quarter-wave monopole, and full-wave loop lengths for any frequency.
Capacitance Calculator
Parallel-plate, charge-voltage, energy stored, RC time constant, series and parallel combinations — all in one tool.
Inductance Calculator
Calculate inductance, reactance, energy, RL time constant and series/parallel combinations.
Resistivity Calculator
Calculate wire resistance, resistivity, length or cross-sectional area — with temperature correction.
Magnetic Force Calculator
Calculate Lorentz force on a charge, on a wire, or between two parallel wires — solve for any variable.
Decibel to Watt Calculator
Convert dB levels to watts (and watts to dB) with full working shown.
ADC Resolution Calculator
Compute LSB voltage, SNR, ENOB, quantisation noise and dynamic range for any ADC.
Amps to Watts Calculator
Convert amps to watts (or watts to amps) for DC, AC single-phase and AC three-phase circuits.
Capacitor Energy Calculator
Calculate the energy stored in a capacitor — plus series/parallel networks and RC discharge power.
Frequency to RPM Calculator
Convert Hz, kHz, rad/s and RPS to RPM — and back — instantly.
kVA to kW Calculator
Convert apparent power to real power instantly — single-phase and three-phase.
kW to kVA Calculator
Convert real power (kW) to apparent power (kVA) using power factor.
Power Dissipation Calculator
Calculate real, apparent and reactive power for DC circuits, AC single-phase and three-phase systems, plus junction temperature from thermal resistance.
Three-Phase Power Calculator
Calculate kW, kVA, kVAR, current and voltage for balanced three-phase AC systems.
Voltage Divider Output Calculator
Compute loaded and unloaded Vout, loading error, power, and nearest E-series resistor.
Watts to Amps Calculator
Convert watts to amps for DC, single-phase AC, and three-phase AC circuits.
Wire Resistance Calculator
Calculate conductor resistance, voltage drop and power loss for any material, length and cross-section.
Conduit Fill Calculator
Check NEC conduit fill compliance — pick a conduit, add wires, get the fill percentage instantly.
Motor FLA Calculator
Calculate full load amperes for single-phase and three-phase AC motors.
PWM Duty Cycle Calculator
Instantly compute duty cycle, frequency, t-on, t-off, period, average voltage, RMS voltage, and power for any PWM signal.
Automotive
Boiler Horsepower & Steam Output Calculator
Convert boiler horsepower to BTU/h, kW, and lbs/hr of steam, plus reverse from kW
G-Code Speed & Feedrate Calculator
Convert mm/s print speeds to G-code feedrate (mm/min) values
Hunting Wind Chill & Effective Temperature Calculator
Calculate wind chill and the clothing layers you need to hunt in the cold
Motor Horsepower to kW Converter
Convert mechanical, metric, and electrical horsepower to kW, plus shaft torque
Refrigeration System Compression Ratio Calculator
Calculate compression ratio from suction and discharge pressures to diagnose compressor health
Automotive Gear Ratio & Speed Calculator
Calculate vehicle speed from RPM, gear ratio, final drive, and tire size
Gear Ratio & Speed Calculator
Compute output RPM, torque ratio, and speed from gear tooth counts
Lathe Turning Horsepower Calculator
Estimate required lathe HP for a turning pass from depth of cut, feed, and material
Milling Horsepower Calculator
Estimate spindle power required for a face-milling or end-milling cut
Plasma Cut Speed Calculator
Find optimal plasma cut speed (IPM) for any steel thickness and amperage
True Airspeed (TAS) Calculator
Calculate true airspeed from indicated airspeed, altitude, and temperature
MIG Wire Feed Speed Calculator
Calculate deposition rate and wire-feed speed from amperage and wire diameter
Engineering Notation Converter
Express numbers in engineering notation (exponents of 3)
FIRE Retirement Calculator
Find your FIRE number and how long until you reach it.
Horsepower to Watts Converter
Convert mechanical horsepower to watts and back, instantly.
Retirement & FIRE Planner
Project your portfolio to retirement, find your FIRE number, and see if it lasts.
Retirement Countdown
Live countdown to the day you reach your target retirement age.
RC Gear Ratio Calculator
Calculate pinion, spur and top speed for your RC car build.
Ackermann Angle Calculator
Calculate ideal inner and outer steer angles, turning radius and Ackermann percentage for any vehicle geometry.
Air-Fuel Ratio Calculator
Calculate AFR, lambda, and equivalence ratio for any fuel — gasoline, diesel, ethanol, methanol, hydrogen and more.
Brake Horsepower Calculator
Calculate BHP from torque and RPM, a Prony brake, or BMEP — with full step-by-step working.
Compression Ratio Calculator
Calculate engine compression ratio — or solve for bore, stroke, or clearance volume.
Engine CC to HP Calculator
Convert engine displacement to horsepower using four engineering methods.
Engine Displacement Calculator
Calculate engine displacement, bore, stroke or cylinder count from any three variables.
Final Drive Ratio Calculator
Solve ring/pinion ratios, vehicle speed, engine RPM and tyre size in one tool.
Fuel Injector Size Calculator
Find the right injector size for your target horsepower in seconds.
Horsepower to Torque Calculator
Convert between horsepower, torque and RPM with full step-by-step working.
Intercooler Calculator
Calculate charge-air temperature drop, pressure loss, density gain and estimated power increase from your intercooler.
Quarter-Mile Calculator
Predict your drag-strip ET and trap speed from horsepower and weight.
Tire Diameter Calculator
Find overall diameter, sidewall, circumference and revs/mile — plus speedometer correction when swapping sizes.
Tire Size Calculator
Decode any P-metric tire code and compare two sizes in seconds.
Turbo Size Calculator
Find the right turbocharger for your engine — compressor flow, pressure ratio, inducer size and shaft speed.
Wheel Offset Calculator
Calculate backspacing, lip clearance and track change from ET offset.
0-60 mph Estimator
Estimate your car''s 0–60 mph time from weight and horsepower.
Boost Pressure Calculator
Convert boost gauge readings, solve pressure ratio, model charge-air density and check injector duty cycle — all in your browser.
Gear Ratio & Speed Calculator
Work out vehicle speed, RPM, gear ratios and final drive from tyre size and transmission data.
Speedometer Error Calculator
Find out how inaccurate your speedo really is — and what your true speed is.
Volumetric Efficiency Calculator
Measure how well your engine breathes — four methods, instant results.
Music & Audio
BPM to Delay Time (ms) Calculator
Find the perfect delay time in milliseconds for any BPM and note value
BPM to Reverb Pre-Delay Calculator
Sync reverb pre-delay to tempo for rhythmically coherent wet sounds
Capo Chord Transposer
Find real chord names when using a capo at any fret position.
Chord Interval Finder
Identify the intervals and inversions present in any chord voicing
Compressor Attack & Release to BPM Calculator
Set musically synced compressor attack and release times from BPM
Guitar Fret Spacing Calculator
Calculate fret positions for any scale length using the rule of 18
Metronome Math Calculator
Turn BPM and a bar count into exact beat, bar and total durations.
Sample Chop BPM Grid Calculator
Find where to cut a sample loop to keep it in time at any BPM
Scale & Chord Builder
Generate the note list for any scale or chord in any root key.
Semitone & Cents Interval Calculator
Calculate frequency ratios, semitones, and cents between two pitches
Song Key Transposer
Transpose chord charts and key signatures up or down any number of semitones
Speaker Impedance Calculator
Work out the total load for any series or parallel speaker wiring.
Guitar String Tension Calculator
Calculate string tension for any gauge, scale length, and tuning.
Ported Subwoofer Box Volume & Port Calculator
Design a ported/bass-reflex subwoofer enclosure with a tuned port
Tap Tempo BPM Calculator
Tap a button to measure BPM and get delay times instantly
Tempo-to-Note-Grid Reference Table
Full table of note subdivision durations in ms for any BPM
Time Signature Note Value Converter
Find the exact duration of every note value at any tempo and meter.
BPM to Milliseconds Calculator
Turn any tempo into delay and note-length times in milliseconds.
Note Frequency Calculator
Find the exact frequency in Hz for any musical note and octave.
Speaker Box Volume Calculator
Design sealed and ported enclosures using Thiele-Small parameters.
Speaker Impedance Calculator
Calculate total impedance for series, parallel and mixed speaker wiring in seconds.
Subwoofer Port Length Calculator
Calculate the exact port tube length to hit your target bass tuning frequency.
BPM to Milliseconds Calculator
Convert any tempo to exact delay, echo and reverb times — straight, dotted and triplet.
Capo Transpose Calculator
Find the right capo fret and open chord shape for any key — instantly.
Cents to Frequency Calculator
Convert pitch intervals in cents to exact frequencies — and back.
Chord Finder
Build any chord by root and type, or identify a chord from its notes — with audio playback.
Guitar String Tension Calculator
Find the exact tension on every string — or the right gauge for a target feel.
Key Transpose Calculator
Transpose any song to a new key instantly — diatonic chords, scale notes and full chord charts.
Semitone Interval Calculator
Pick any two notes and instantly see the semitone distance, cents, frequency ratio and interval name.
Time Signature Calculator
Beat durations, bar lengths, compound vs simple meters, polyrhythm grids and tap tempo — all in one tool.
BPM Delay Calculator
Convert BPM to delay times, reverse-engineer tempo from a known delay, tap-detect tempo and model feedback decay — all in one tool.
Metronome & BPM Tapper
Tap the beat, measure your tempo, and hear a precise click-track with note-delay tables.
Scale Degree Calculator
Instantly see every note, Roman numeral and interval in any musical scale.
Gaming
Catan Dice Roll Probability Analyzer
Find the best Catan settlements by dice probability
Dice Tower & Anydice Probability Calculator
Compute probabilities for exploding dice, drop-lowest, and pool systems
D&D Advantage/Disadvantage Calculator
How much does advantage actually help your D&D rolls?
D&D 5e Race & Subrace Trait Reference
Look up racial traits, speeds, and darkvision for any D&D 5e race
D&D Multiclass Proficiency & Spell Slot Tracker
Get proficiency bonus and combined spell slots for multiclass builds
D&D Custom Monster CR Builder
Calculate challenge rating for a custom D&D 5e monster
D&D Damage Per Round (DPR) Calculator
Calculate average DPR for any D&D 5e attack or spell
D&D Dice Probability Calculator
Exact probabilities for any D&D dice roll combination
D&D Encounter CR / XP Budget Calculator
Balance D&D 5e encounters by the book using XP thresholds
D&D Hit Points Calculator
Max and average HP for any D&D 5e character build
D&D Initiative Tracker
Track initiative order and HP for any D&D encounter
D&D Treasure / Loot Generator
Generate hoard or individual treasure by CR using DMG tables
D&D 5e Point Buy Calculator
Allocate ability scores with the D&D 5e point-buy system
D&D Proficiency Bonus & Skill Check Calculator
Calculate all skill and saving throw bonuses for any D&D character
D&D Wild Magic Surge Probability Calculator
Track and calculate Wild Magic Surge odds for sorcerers
D&D XP to Next Level Tracker
Track XP and milestone progression for any D&D 5e character
MTG Draft Pick Evaluation Tool
Rank your MTG draft picks by power, color commitment, and curve
MTG Combo Turn Estimator
Estimate the average turn you'll assemble a 2- or 3-card combo
MTG Deck Archetype Analyzer
Classify your MTG deck as aggro, midrange, control, or combo
MTG Commander Color Identity Checker
Verify card color identity legality for any EDH Commander deck
MTG Hypergeometric Draw Calculator
Probability of drawing any card combination from your MTG deck
MTG Land Count Optimizer
Find the optimal land count for your Magic deck
MTG Mana Curve Analyzer
Visualize and optimize your Magic: The Gathering mana curve
MTG Mulligan Probability Calculator
Odds of hitting your opening hand requirements in Magic
MTG Infect / Poison Counter Tracker
Track infect damage and poison counters in Magic: The Gathering
MTG Storm Count Calculator
Track your storm count and the copies a Storm spell will make
Custom Dice Pool Probability Table
Calculate the full probability distribution for any dice pool
Red Cell Indices (MCV, MCH, MCHC) Calculator
Compute erythrocyte indices from a CBC to classify anaemia
Neonatal Jaundice Phototherapy Threshold Calculator
Plot total serum bilirubin against gestational-age thresholds
Renal Stone Risk Index Calculator
Urinary supersaturation indices for calcium oxalate and uric acid
Italy Codice Fiscale Decoder & Validator
Decode an Italian Codice Fiscale — date of birth, gender and check digit.
Dice Notation Roller
Roll full RPG dice notation: 3d6+2, 2d20kh1, 4d6dl1, exploding dice and more.
D&D Ability Score Calculator
Roll, buy, or array-assign your D&D 5e stats with modifiers, saving throws and XP thresholds.
Character Level Calculator
Instantly find your RPG character level from XP — D&D 5e, Pathfinder 2e and OSE.
Damage Per Second (DPS) Calculator
Calculate true DPS for any weapon, build or ability rotation in any game.
D&D 5e Encounter XP Calculator
Balance encounters by difficulty — Easy, Medium, Hard or Deadly.
D&D Spell Slot Tracker
Track every spell slot for every D&D 5e caster class in real time.
Experience Points (XP) Calculator
Build D&D 5e encounters, look up level-up thresholds and track character XP — all in one tool.
Loot Roll Generator
Simulate RPG loot tables with weighted drops, rarity tiers, and dice quantities.
MTG Life Counter
Track life totals, poison counters, commander damage and more for Magic - The Gathering.
D&D Critical Hit Calculator
Instantly see crit damage range, average, and full probability distribution.
Dice Probability Calculator
Exact probabilities for any dice roll — 2d6, 3d10, custom polyhedral dice.
Astronomy
Lunar Phase & Moonlight Exposure Calculator
Estimate the EV of moonlight and get shutter, aperture, and ISO for moonlit scenes.
Moon Phase & Illumination Calculator
Calculate moon phase, illumination %, and lunar age for any date
Astrophoto Golden Hour & Astronomical Twilight Calculator
Calculate civil, nautical, and astronomical twilight times for imaging
Sunrise/Sunset Azimuth Angle Calculator
Find the compass direction the sun rises and sets for any date and location.
Telescope Resolving Power & Aperture Guide
Calculate Dawes limit and Rayleigh limit for any telescope aperture
Barlow Lens Effective Focal Length Calculator
Calculate new magnification and focal length with a Barlow lens
Telescope Focal Ratio (f/ratio) Calculator
Calculate focal ratio, speed, and depth of focus for any scope
Telescope Eyepiece Magnification Calculator
Calculate magnification, exit pupil, and true FOV for any eyepiece
Moon Phase Calculator
Find the moon phase and illumination for any date.
Astronomical Unit Converter
Convert astronomical units (AU) to kilometers and back.
Light-Years to Kilometers Converter
Convert light-years to kilometers and back.
Parsecs to Light-Years Converter
Convert parsecs to light-years and back.
Planet Weight Calculator
See how much you would weigh on every planet, the Moon and the Sun.
Telescope Magnification Calculator
Find your telescope magnification from focal length and eyepiece.
Sunrise & Sunset Calculator
Find exact sunrise, solar noon, and sunset times for any location and date.
Golden Hour Calculator
Find the exact golden hour and blue hour windows for any location and date.
Blue Hour Calculator
Find exact blue hour, golden hour and twilight times for any location and date.
Next Full Moon Calculator
Find the exact date and time of the next full moon — and the ones after it.
Sunrise & Sunset Time Calculator
Find exact sunrise, sunset, solar noon and golden hour for any location and date — no internet needed.
Telescope Magnification Calculator
Magnification, exit pupil, true FOV, limiting magnitude and resolving power — all in one tool.
Angular Resolution Calculator
Rayleigh criterion, Dawes limit, Abbe limit, pixel scale and more — all in your browser.
Day Length Calculator
Sunrise, sunset, golden hour and day length for any location and date — no internet required.
Focal Ratio Calculator (f-number / f-stop)
Calculate f-number, focal length, aperture diameter, depth of field and exposure equivalents.
Light-Year Distance Calculator
Convert cosmic distances between light-years, parsecs, AU, km and more — with light travel time.
Moon Phase Tonight
See the current moon phase, illumination, distance and next phase dates — instantly.
Redshift Calculator
Compute cosmological distances, lookback time and recession velocity from redshift z.
Solar Noon Calculator
Find the exact moment the sun peaks in the sky — plus sunrise, sunset and golden hour.
Star Magnitude Calculator
Compare star brightness, find absolute magnitude, and compute telescope limits.
Geography & GPS
Bolt Circle Coordinate Calculator
Calculate XY coordinates for equally spaced bolt-circle holes
Compass Deviation & Variation Correction Tool
Convert true, magnetic, and compass bearings using the TVMDC method
Great-Circle Aviation Route Calculator
Calculate great-circle distance, initial track, and waypoints between airports
Nautical Distance Calculator (Rhumb & Great-Circle)
Calculate sea distance between two ports by rhumb-line and great-circle methods
3D Distance Calculator
Find the straight-line distance between two points in three-dimensional space.
Haversine Distance Calculator
Calculate the great-circle distance between any two points on Earth.
Latitude & Longitude Converter
Convert coordinates between DD, DDM, DMS, radians and UTM — plus great-circle distance and bearing.
Bearing Calculator
Find the compass bearing and great-circle distance between any two points on Earth.
Compass Bearing Calculator
Find the true bearing and great-circle distance between any two points on Earth.
Coordinate Distance Calculator
Great-circle distance, bearing and midpoint between two GPS coordinates.
GPS Coordinate Formatter
Convert GPS coordinates between DD, DDM, DMS, UTM, Geohash, Plus Code, Maidenhead and MGRS instantly.
Great-Circle Distance Calculator
Compute the shortest path between any two points on Earth — with bearings, midpoint, and Vincenty precision.
Map Scale Calculator
Convert map distances to real-world distances — and find any unknown in the scale equation.
UTM Coordinate Converter
Convert between UTM grid references and latitude/longitude in both directions.
Statistics & Probability
Lorcana Deck Draw Probability Calculator
Probability of drawing Lorcana cards in your opening hand
Motor KV & Propeller Combination Calculator
Match motor KV rating to the right propeller for your RC build
Pokémon TCG Draw Probability Calculator
Hypergeometric odds for Pokémon card draws and combos
Pokémon Prize Card Probability
Odds your key cards are prized in a Pokémon game
Yu-Gi-Oh! Combo Probability Calculator
Hypergeometric odds for Yu-Gi-Oh opening hands and combos
Combinations & Permutations Calculator
Compute nCr, nPr, and factorials instantly in your browser.
Z-Score Calculator
Convert a value to a standard score — and back.
Confidence Interval Calculator
Mean ± margin of error at 80–99% confidence.
Correlation Calculator
Pearson r for two paired data series.
Probability Calculator
Complement, AND/OR for independent events, and Bayes.
Sample Size Calculator
How many responses you need for a survey.
Statistics Calculator
Paste numbers and get mean, median, mode, range, variance, standard deviation, quartiles and sum instantly.
Standard Deviation Calculator
Sample and population standard deviation with a full step-by-step working table.
Permutation and Combination Calculator
Compute nPr and nCr with a full factorial breakdown and exact big-number math.
Expected Value Calculator
Calculate E[X] for discrete, Bernoulli, uniform and normal distributions — with full working shown.
Kelly Criterion Calculator
Find the mathematically optimal bet size to maximise long-run bankroll growth.
Linear Regression Calculator
Fit a least-squares line, get R², ANOVA table, residuals and predictions instantly.
P-Value Calculator
Instantly compute exact p-values for Z, t, and chi-squared tests — with formula working shown.
Poisson Distribution Calculator
Calculate exact, cumulative and range probabilities for any Poisson process.
Binomial Probability Calculator
Exact P(X = k), cumulative CDF and full distribution — with a bar chart.
Combinations with Repetition Calculator
Count multiset selections using the stars-and-bars formula.
Correlation Coefficient Calculator
Calculate Pearson r, R², regression line and scatter plot instantly.
Z-Score to Percentile Calculator
Convert any z-score to a percentile — or find the z-score for any percentile.
Birthday Paradox Calculator
Discover how quickly shared birthdays become probable in a group.
Geometry
CO2 Cylinder Duration Calculator
Estimate how long a CO2 cylinder will last in your planted tank
Bokeh Circle of Confusion Size Calculator
Calculate the physical diameter of bokeh discs at any aperture and distance
Shell Thickness & Perimeter Calculator
Calculate total shell thickness from perimeter count and line width
Circle of Fifths Key Relationship Tool
Find relative and parallel keys, borrowed chords, and modulation paths
Circle of Confusion Calculator
Find the right circle of confusion for your sensor and viewing setup
Lightning Protection Rolling Sphere Calculator
Determine air terminal zones of protection per the NFPA 780 rolling sphere method.
Refrigerant Recovery Cylinder Capacity Calculator
Check recovery cylinder remaining capacity without exceeding the 80% fill limit
Circle Calculator
Radius, diameter, circumference and area from any one value.
Triangle Calculator
Area, perimeter and angles from three side lengths.
Pythagorean Theorem Calculator
Solve a² + b² = c² for the hypotenuse or a missing leg.
Body Surface Area Calculator
BSA in m² by Du Bois, Mosteller and Haycock formulas.
Sphere Calculator
Volume and surface area of a sphere from its radius.
Cone Calculator
Volume, surface area and slant height of a right circular cone.
Cylinder Calculator
Volume and surface area of a right circular cylinder.
Pyramid Calculator
Volume and surface area of a rectangular-base pyramid.
Trapezoid Calculator
Area, perimeter and midsegment of a trapezoid.
Ellipse Calculator
Area, perimeter, eccentricity and axes of an ellipse.
Polygon Area Calculator
Area, perimeter and angles of any regular polygon.
Hexagon Calculator
Area, perimeter, diagonals and apothem of a regular hexagon.
Sector & Arc Calculator
Arc length, sector area and chord from radius and angle.
Parallelogram Calculator
Area, height, perimeter and diagonals of a parallelogram.
Right Triangle Trig Solver
Solve any right triangle from two known values — sides and angles.
Law of Cosines Calculator
Solve any triangle from three sides or two sides and an angle.
Pentagon Calculator
Area, perimeter, diagonal and radii of a regular pentagon.
Octagon Calculator
Area, perimeter, diagonals and radii of a regular octagon.
Rhombus Calculator
Area, perimeter, diagonals and angles of a rhombus.
Regular Polygon Calculator
Area, perimeter, radii and angles for any regular n-gon.
Annulus Calculator
Area, width and circumferences of a ring between two circles.
Ramp Slope Calculator
Angle, percent grade, rise/run ratio and ADA compliance — instantly.
Rise Over Run Calculator
Slope, angle, grade and pitch from any rise and run — or solve in reverse.
Cube Volume Calculator
Instantly find the volume, surface area and diagonals of any cube — solve from any known value.
Ellipsoid Volume Calculator
Compute volume, surface area and solve for any semi-axis — all in your browser.
Equilateral Triangle Calculator
Instantly find side, height, area, perimeter, inradius and circumradius — solve from any one value.
Pyramid Volume Calculator
Volume, surface area and slant height for any pyramid — square, rectangular, triangular or hexagonal base.
Rectangular Prism Volume Calculator
Instantly find volume, surface area and space diagonal — or solve for any missing dimension.
Right Triangle Calculator
Solve any right triangle from two known values — sides, angles, area and trig ratios instantly.
Slope-Intercept Calculator
Find the equation y = mx + b from two points, solve for x or y, and see the diagram.
Sphere Volume Calculator
Instantly find volume, surface area, diameter or radius — solve for any variable.
Triangle Area Calculator
Find the area of any triangle: base-height, Heron's formula, SAS, or coordinates.
Hexagon Area Calculator
Find the area of a regular hexagon from any measurement you have.
Circle Diameter Calculator
Find diameter, radius, circumference and area — solve from any one value.
Cone Volume Calculator
Calculate cone volume — or solve for radius or height from a known volume.
Rhombus Area Calculator
Find rhombus area from diagonals, side + height, or side + angle — with full working.
Torus Volume Calculator
Find volume, surface area and all torus dimensions — solve for any variable.
Trapezoid Area Calculator
Instantly find the area of any trapezoid — or solve for any missing dimension.
Triangle Angle Calculator
Find every angle and side of any triangle from three known values.
Annulus Area Calculator
Find the ring area, or solve for outer or inner radius from a known area.
Arc Length Calculator
Find arc length, radius or central angle — with working steps and a live diagram.
Capsule Volume Calculator
Calculate capsule volume — or solve for radius or cylinder height from a known volume.
Circle Area Calculator
Area, radius, diameter and circumference — solve for any one from any other.
Circle Equation Calculator
Find the standard form, general form, area, arc length, chord and sector — instantly.
Cylinder Volume Calculator
Find volume, surface area or a missing dimension of any cylinder instantly.
Ellipse Area Calculator
Compute ellipse area, perimeter, eccentricity — or solve for any missing semi-axis.
Frustum Volume Calculator
Find the volume of a truncated cone — or solve back for height or radius.
Hemisphere Volume Calculator
Calculate the volume, curved surface area and base area of any hemisphere instantly.
Heron's Formula Calculator
Find the area of any triangle from its three side lengths — no angles needed.
Law of Sines Calculator
Solve any triangle from two angles + one side, or two sides + an opposite angle.
Octagon Area Calculator
Area, perimeter, diagonals and radii of a regular octagon — solved from any measurement.
Parallelogram Area Calculator
Find the area of any parallelogram — or solve for base or height — instantly.
Regular Polygon Area Calculator
Area, perimeter, radii and angles for any regular n-gon — solve from side, radius or perimeter.
Sector Area Calculator
Area, arc length, chord and perimeter from any two of: radius, angle, or area.
Tetrahedron Volume Calculator
Calculate the volume of a regular tetrahedron — or find the edge length from a known volume.
Triangular Prism Volume Calculator
Find the volume (and surface area) of any triangular prism instantly.
Circle Circumference Calculator
Circumference from radius, diameter or area — solve any way around.
Pentagon Area Calculator
Area, perimeter, inradius, circumradius and diagonal — solve from any measurement.
Sphere Surface Area Calculator
Find the surface area of any sphere — or back-calculate the radius from a known area.
Diagonal of a Rectangle Calculator
Find the diagonal, width, height, angles, area and perimeter — with full step-by-step working.
Law of Cosines Solver
Solve any triangle from any three pieces — all five congruence cases with full step-by-step working.
Perimeter Calculator
Instantly find the perimeter of 14 shapes with step-by-step working.
Surface Area Calculator
Instant surface area for 10 shapes — sphere, cylinder, cone, prism, pyramid, torus and more.
Unit Circle Calculator
Enter any angle and instantly read sin, cos, tan, csc, sec, cot — with a live diagram.
Math & Algebra
Tape Machine Operating Level Calculator
Convert between nWb/m tape flux levels and VU/dB reference levels
Aquarium Evaporation & ATO Top-Off Calculator
Estimate daily evaporation and size your ATO reservoir
Water-to-Grain Ratio (Quarts per Pound) Calculator
Find the optimal mash thickness for your recipe and equipment
Bittering to Aroma Hop Ratio Calculator
Balance bittering, flavor, and aroma hop additions by IBU contribution
BU:GU Ratio Calculator
Check balance between bitterness units and gravity units in your recipe
dB to Power Ratio Converter
Convert decibel values to power ratios using the 10·log10 formula.
E-Steps Calibration Calculator
Calculate new extruder steps-per-mm value from a calibration measurement
Gravity to Degrees Balling Converter
Convert specific gravity readings to the Balling sugar scale
Equipment Grounding Conductor Sizing (NEC 250.122)
Select minimum EGC wire size from the NEC 250.122 table by OCPD rating
Lager Lagering Duration Calculator
Calculate minimum lagering time at temperature for clean lager production
Photo Aspect Ratio & Crop Calculator
Find crop dimensions and lost pixels for any target aspect ratio
Bellows Draw Magnification Ratio Table
Generate a magnification table for all bellows extension lengths
Shutter Speed Fraction to Decimal Converter
Convert fractional shutter speeds to decimal seconds and find the EV gap between two speeds.
Polar Alignment Drift Rate Calculator
Calculate polar alignment error from measured drift rate
Polyrhythm & LCM Calculator
Find the cycle length and grid resolution for any polyrhythm.
Sensor Aspect Ratio to Print Size Matcher
Find standard print sizes that match your camera's native aspect ratio with the least cropping.
RC Drone Thrust-to-Weight Ratio Calculator
Calculate thrust-to-weight ratio for any multirotor or fixed-wing
Resin & Epoxy Mixing Ratio Calculator
Calculate part A and part B volumes for any epoxy by mix ratio
Sample Rate Conversion Ratio Calculator
Get the resampling ratio and output sample count between two rates.
Soap Recipe Oil Percentage Calculator
Balance soap oil percentages for lather, hardness, and longevity
Sulfate to Chloride Ratio Calculator
Balance SO4:Cl ratio for hoppy vs malty beer water profiles
TCG Card Pop Report & Market Math Calculator
Analyze PSA/BGS pop report data and grade distribution math
Wort Boil Concentration Factor
Calculate how much gravity increases as wort boils down
XY Steps-Per-mm Calibration Calculator
Correct X/Y axis steps-per-mm from measured vs requested movement.
Phenytoin Free Fraction Estimator in Renal Failure
Estimate unbound phenytoin when both albumin and GFR are low
Sine Bar / Sine Plate Setup Calculator
Calculate gauge-block stack height for a sine bar at any angle
MBEC / MBIC Ratio Calculator for Biofilm Studies
Compute biofilm eradication and inhibition ratios versus MIC
Carbon Price Impact on Business Cost Calculator
Model how EU ETS or UK ETS carbon price changes affect operating costs
CBM (Cubic Metre) Cargo Calculator
Calculate total cubic metres for ocean, air, or road freight shipments
Compost Recipe C:N Ratio Calculator
Balance carbon and nitrogen inputs in a compost pile using the C:N ratio
Concrete Mix Ratio Calculator
Compute cement, sand, gravel, and water quantities for any mix design
Crop Water Use (ET) Estimator
Estimate daily and seasonal evapotranspiration for major field crops
DeFi Collateral Ratio & Health Factor Calculator
Calculate collateral ratio and health factor for lending protocols like Aave
Pharmacy Dose Rounding Calculator
Round calculated doses to the nearest available tablet or vial strength
ELISA Standard Curve & Sample Concentration Calculator
Fit a 4PL curve and interpolate ELISA sample concentrations
ESG Double Materiality Matrix Builder
Map ESG topics by financial and impact materiality for CSRD reporting
Ether Unit & Scientific Notation Converter
Convert ETH values between ether, gwei, wei, and scientific notation
Feed Conversion Ratio (FCR) Calculator
Calculate feed conversion ratio, feed cost per kg gain, and breakeven feed price
Livestock Feed Ration Calculator
Balance a basic ruminant ration for protein, energy, and dry matter
Fractional Excretion of Sodium (FENa) Calculator
Distinguish pre-renal AKI from intrinsic renal failure
P/F Ratio (PaO₂/FiO₂) Calculator — Berlin ARDS Criteria
Calculate the oxygenation index and ARDS severity classification
Flow Cytometry Compensation Matrix Calculator
Calculate spectral spillover correction from single-stain controls
HbA1c to Average Glucose Converter (eAG)
Convert HbA1c (% or mmol/mol) to estimated average glucose
Health & Safety Risk Matrix Calculator
Calculate a risk rating from likelihood × severity on a 5×5 or 3×3 matrix
UK ICO Data Protection Registration Checker
Check if you must register with the UK ICO and estimate your data protection fee tier
Immigration Priority Date Tracker
Check whether your priority date is current against the visa bulletin
Infusion Concentration & Rate Calculator
Convert drug mass/volume to mcg/kg/min or mg/hr infusion rates
INR from PT Ratio & ISI Calculator
Convert prothrombin time and reagent ISI to a standardised INR
MAC (Minimum Alveolar Concentration) Calculator
Age-adjusted MAC for volatile anaesthetic agents
Crypto Wallet Age & HODL Duration Calculator
Calculate HODL duration and ROI from any manually-entered acquisition date
Oxygen Saturation Altitude Correction Calculator
Adjust expected SpO2 and PaO2 ranges for altitude
Percent Solution Calculator (w/v, w/w, v/v)
Calculate w/v, w/w, or v/v percentage concentrations
Perioperative Fasting Duration Calculator
Calculate safe pre-op fasting end-times from scheduled surgery time
Primer Tm (Melting Temperature) Calculator
Estimate primer melting temperature by nearest-neighbour or basic method
Chemical Reaction Theoretical & Percent Yield Calculator
Calculate theoretical yield and reaction efficiency from stoichiometry
Scope 3 Business Travel Emissions Calculator
Calculate Scope 3 Category 6 business travel CO2e across all transport modes.
Soil Cation Exchange Capacity & Base Saturation Tool
Calculate CEC, base saturation, and lime requirement from soil test results
Spirometry % Predicted Calculator (GLI-2012)
Classify FEV1, FVC, and FEV1/FVC against reference values
Sprayer Calibration Calculator
Calibrate sprayer output in GPA from nozzle flow, speed, and row spacing
Weld Joint Preparation Calculator
Calculate groove angle, root face, and root opening for AWS-standard joints
Multi-Pass Weld Sequence Planner
Calculate passes, pass size, and a distortion-control sequence for any groove
Western Blot Sample Preparation Calculator
Normalise protein samples to equal loading mass for SDS-PAGE
Date Add/Subtract Duration
Add or subtract days/months/years to/from a given date
Collatz Sequence Generator
Generate the Collatz (3n+1) sequence for any starting integer
Continued Fraction Converter
Express any real number as a continued fraction expansion
Detroit Cost-of-Living Index — 80 vs US Average of 100
Compare Detroit living costs (composite index 80) to the US national average across housing, food, and more.
Duration Humanizer
Convert a number of seconds into a 2 hours, 34 minutes form
Fibonacci Sequence Generator
Generate the first N terms of the Fibonacci sequence
Float to Rational Fraction Converter
Find the simplest rational fraction approximating a decimal
Los Angeles Cost-of-Living Index — LA vs US Average
Compare Los Angeles living costs (index 173) to the US national average of 100.
Modular Exponentiation Calculator
Compute (base^exp) mod m efficiently using fast exponentiation
Ratio Simplifier
Reduce a ratio like 24:36 to its simplest form
Extended Roman Numeral Converter
Convert numbers beyond 3999 using extended Roman numerals with vinculum overbars.
Fraction to Decimal Converter
Turn any fraction — proper, improper or mixed — into a decimal.
Decimal to Fraction Converter
Convert any decimal into its simplest fraction or mixed number.
Mean, Median & Mode Calculator
Get the mean, median, mode, range and sum of any list of numbers.
Quadratic Formula Solver
Solve ax² + bx + c = 0 for real or complex roots.
Percentage Change Calculator
Work out the percentage increase or decrease between two values.
Business Days Calculator
Count working days between two dates, holidays excluded.
CGPA to Percentage Calculator
Convert CGPA to a percentage using CBSE, VTU, or a custom multiplier.
Romania CNP Decoder
Decode birth date, sex and county from a Romanian CNP.
Percentage of a Number Calculator
Quickly find what a percentage of any number is.
Tip Percentage Table
See the tip and total for a bill across every common tip percentage at once.
Percentage Increase / Decrease Calculator
Find the % change between two numbers, or apply a % rise or fall.
Proportion Solver (Cross-Multiplication)
Solve a/b = c/d for the missing value by cross-multiplication.
Exponent Calculator (Power Calculator)
Raise any base to any power — including negative and fractional exponents.
Logarithm Calculator (log, ln, log₂, any base)
Compute log base 10, natural log, log base 2 or any custom base.
Factorial Calculator (n!)
Compute exact factorials of any non-negative integer with BigInt.
Time Duration Adder
Add and subtract hours, minutes and seconds across a list of durations.
2x2 Matrix Calculator
Add, subtract, multiply, and find the determinant or inverse of 2x2 matrices.
Prime Factorization Calculator
Break any whole number down into its prime factors instantly.
Percentage of Total Calculator
Turn a list of values into each value's share of the total.
Cubic Meters to Liters Converter
Convert m³ to liters (and back) instantly.
Acceleration Calculator
a = (v_f − v_i) ÷ t — solve for acceleration, velocity, or time.
Percentile Calculator
Find any percentile of a data set — or a value's rank.
Degrees to Radians Converter
Convert degrees to radians instantly — rad = ° × π ÷ 180. Free, browser-only.
Radians to Degrees Converter
Convert radians to degrees instantly — ° = rad × 180 ÷ π. Free, browser-only.
Percentage Difference Calculator
Find the percentage difference between two values.
Weighted Average Calculator
Average values that carry different weights.
Rounding Calculator
Round numbers to decimals, multiples or whole numbers.
Add Business Days
Add or subtract business days from a date, skipping weekends.
2D Vector Calculator
Add, subtract, dot, cross and find the angle between 2D vectors.
Complex Number Calculator
Add, subtract, multiply and divide complex numbers with modulus and argument.
Set Operations Calculator
Union, intersection, difference and symmetric difference of two sets.
Modular Exponentiation Calculator
Compute (base ^ exponent) mod modulus for huge numbers.
Percentage to GPA Converter
Convert a percentage grade to a 4.0-scale GPA and letter.
Class Rank Percentile Calculator
Turn your class rank into a percentile and top-percent figure.
Attendance Percentage Calculator
Check your attendance percentage and absences left.
Debt-to-Income Ratio Calculator
See your DTI ratio and where you stand with lenders.
Decision Matrix Maker
Score options against weighted criteria and find the ranked winner.
Date Duration Calculator
Exact years, months, days and hours between two dates — plus add or subtract a duration.
Roman Numeral Math Calculator
Add, subtract, multiply and divide directly in Roman numerals — with a full step-by-step explanation.
Math Worksheet Generator
Build printable arithmetic worksheets with a matching answer key.
Aspect Ratio Crop & Letterbox Calculator
Convert any resolution to a new aspect ratio: crop, letterbox, area kept and storage cost.
Debt-to-Income Ratio Calculator
Add up your monthly debts and income to see your DTI and where it lands with lenders.
GCD & LCM Calculator
Find the greatest common divisor and least common multiple of any integers — with Euclid steps.
Ratio Calculator
Simplify ratios, solve proportions and scale ratios — with the working shown.
Fraction Calculator
Add, subtract, multiply and divide fractions with full working shown.
Percentage Calculator
One tool for every percentage question — of, is-what-%, change, difference, increase, decrease and reverse.
Prime Number Checker
Test any number for primality, factorise it, and list every prime up to N.
Quadratic Equation Solver
Enter a, b, c and get the roots, discriminant, vertex, axis and full working.
Scientific Notation Converter
Convert decimals to scientific, engineering and E-notation with significant figures.
Cold Brew Ratio Calculator
Perfect your coffee-to-water ratio, yield, servings and caffeine estimate.
Compost Ratio Calculator
Find the perfect carbon-to-nitrogen ratio for fast, odour-free composting.
Espresso Ratio Calculator
Dial in the perfect brew ratio, extraction yield and TDS for every shot.
Kombucha Ratio Calculator
Perfect your 1F brew ratios and 2F carbonation sugar — batch-size aware.
Dot Product Calculator
Compute dot products, angles, projections and cross products for 2D–5D vectors.
Matrix Determinant Calculator
Find the determinant of any 2×2 to 6×6 matrix with full step-by-step working.
Modular Exponentiation Calculator
Compute (a^b) mod m instantly — even for enormous cryptographic-size exponents.
Exponential Growth & Decay Calculator
Solve N(t) = N₀·e^(rt) — find future value, initial value, rate, or time.
Matrix Multiplication Calculator
Multiply, invert, transpose or find the determinant of matrices up to 6x6.
Cross Product Calculator (3D Vectors)
Compute a × b instantly — magnitude, angle, area and unit normal.
Vector Magnitude Calculator
Find the length of any 2-D, 3-D or n-D vector, get the unit vector and direction angles.
Cubic Equation Solver
Find all three roots of ax³ + bx² + cx + d = 0 with full working shown.
Decimal to Fraction Calculator
Convert any decimal — including repeating decimals — to its exact simplest fraction, with full step-by-step working.
Big Factorial Calculator — Exact BigInt Up to 10,000!
Compute exact factorials with BigInt, digit counts, scientific notation and full working steps.
Fibonacci Calculator
Find any Fibonacci number instantly, explore the golden ratio, and visualise the spiral.
Fraction to Percent Calculator
Convert any fraction, mixed number, or decimal to a percentage instantly.
Geometric Sequence Calculator
Find any term, the common ratio, or the sum of a geometric sequence instantly.
Greatest Common Factor Calculator
Find the GCF of two or more numbers with full prime-factor working and Euclid steps.
Percent Off Calculator
Find the sale price, saving, or original price for any discount instantly.
Quadratic Formula Calculator
Solve ax² + bx + c = 0 instantly — real and complex roots, full working, parabola diagram.
Simplify Fraction Calculator
Reduce any fraction to its lowest terms instantly, with full working shown.
System of Equations Solver
Solve 2x2 and 3x3 linear systems instantly with full working steps.
Least Common Multiple Calculator
Find the LCM of any list of integers — with prime-factor table, step-by-step working, and a cycle diagram.
Arithmetic Sequence Calculator
Find any term, the sum, or a missing value in an arithmetic sequence.
Cross-Multiplication Calculator
Solve any proportion instantly — enter three values, get the fourth.
Percent Error Calculator
Find the percent error between a measured and accepted value — or solve backwards.
Proportion Calculator
Solve any missing value in a/b = c/d instantly using cross-multiplication.
Summation Calculator
Compute sigma notation sums instantly — custom expressions, arithmetic, geometric, power, and harmonic series.
WACC Calculator
Compute the Weighted Average Cost of Capital with CAPM equity cost and the full tax shield.
Angle Between Vectors Calculator
Find the angle between any two 2-D, 3-D, or 4-D vectors — with full working.
Sine, Cosine & Tangent Calculator
Compute all six trig functions, inverses, unit-circle coordinates and wave graphs instantly.
Cartesian to Polar Calculator
Convert (x, y) to (r, θ) — or reverse — with full working and unit options.
Degrees to Radians Calculator
Convert degrees to radians, see trig values, arc length, sector area and angular motion — all in one tool.
Inverse Trig Calculator
Find angles from ratios — arcsin, arccos, arctan, arccot, arcsec, arccsc and the hyperbolic inverses.
Polar to Cartesian Calculator
Convert polar (r, θ) to Cartesian (x, y) — or reverse — instantly with step-by-step working.
Radians to Degrees Calculator
Convert any angle — see the formula, trig values, DMS and unit-circle coordinates instantly.
Trigonometric Identity Calculator
Verify and evaluate every major trig identity — basic, Pythagorean, double-angle, half-angle, sum-difference, product-to-sum, power-reduction, co-function and inverse.
Brine Ratio Calculator
Find the exact salt-to-water ratio for any brine: pickling, curing, fermentation or food-science.
Coffee-to-Water Ratio Calculator
Get the perfect coffee ratio for any brew method — pour-over, espresso, French press and more.
Ganache Ratio Calculator
Get the exact chocolate-to-cream ratio for truffles, glazes, tarts and more.
Rice Water Ratio Calculator
Perfect rice every time — correct water for any rice type, method and altitude.
Golden Ratio Typography Calculator
Generate a perfect type scale, line heights and measure using φ = 1.618.
Modular Scale Calculator
Generate harmonious type and spacing scales from a base size and musical ratio.
Time Duration Between Two Dates Calculator
Find the exact duration between any two dates — in years, months, days, hours, minutes and seconds.
Food, Cooking & Brewing
Beeswax Food Wrap Recipe Calculator
Calculate beeswax, pine resin, and jojoba oil for food-wrap fabric
Keg Carbonation (CO2) Calculator
Set the correct CO2 regulator pressure for your target carbonation at serving temperature.
Mash Efficiency Calculator
Calculate mash conversion, lauter, and brewhouse efficiency from measured gravity
Wine Potential ABV Calculator
Find potential alcohol from must sugar content in Brix or gravity.
Yeast Pitch Rate Calculator
Calculate the correct amount of yeast to pitch for clean fermentation.
Yeast Starter Calculator
Size a DME starter to reach a target yeast cell count.
Lab Buffer Recipe Generator
Generate gram and molar recipes for Tris, HEPES, PBS, and more
Cooking Measurement Converter
Convert cups, tablespoons, teaspoons, ml and litres for recipes.
Oven Temperature Converter
Convert oven temperatures between °C, °F and gas mark.
Recipe Scaler
Scale a recipe up or down by servings, ingredient by ingredient.
Slow Cooker Time Converter
Convert oven or stovetop times into slow cooker Low and High times.
Yeast Conversion Calculator
Convert between fresh, active dry and instant yeast.
Recipe Cost Calculator
Work out the true cost per serving of any recipe — pack price in, plate cost out.
Cooking Unit Converter
Convert cups, tablespoons, grams and millilitres — density-aware, and scale whole recipes.
Cooking Weight to Volume Converter
Convert grams to cups, tablespoons and teaspoons for any ingredient.
Oven Temperature Converter
Convert between Celsius, Fahrenheit and gas mark with a full reference table.
Beer ABV Calculator
Calculate alcohol by volume, apparent attenuation and calories from OG and FG.
Beer IBU Calculator
Calculate bitterness (IBUs) from hop additions using Tinseth or Rager.
Mash Efficiency Calculator
Know exactly how well your mash converted grain sugars to wort — batch after batch.
Mead ABV Calculator
Find the alcohol content of your mead from original and final gravity readings.
Pizza Dough Calculator
Exact ingredient weights for any number of balls, size, and hydration.
Priming Sugar Calculator
Bottle carbonation sugar amounts for any beer style, volume and temperature.
Wine ABV Calculator
Calculate wine alcohol content from starting and ending specific gravity.
Keg Size Calculator
Convert any keg volume and find out exactly how many pints you will pour.
Meat Curing Calculator
Precise salt, curing salt and sugar amounts for dry or wet cures.
Turkey Cooking Time Calculator
Get the exact cook time, rest time and oven start time for your turkey.
Ham Cooking Time Calculator
Exact oven times for any size ham — bone-in, boneless, fresh or pre-cooked.
Wine Bottles Per Guest Calculator
Find out exactly how many bottles of wine to buy for any event.
Sous Vide Time & Temperature Calculator
Find the exact bath temperature and minimum safe cooking time for any protein.
Butter Conversion Calculator
Convert butter between grams, ounces, cups, sticks, tablespoons and more — with full working shown.
Cooking Temperature Converter
Instantly convert oven temperatures between Celsius, Fahrenheit, Kelvin and UK Gas Mark.
Egg Substitute Calculator
Find the best vegan or allergy-friendly egg replacement for any recipe.
Yeast Conversion Calculator
Convert between active dry, instant, fresh cake, and sourdough starter — instantly.
Slow Cooker Conversion Calculator
Convert any oven or stovetop recipe to slow cooker settings in seconds.
Farming & Garden
Aquarium Alkalinity (KH) & Buffer Calculator
Calculate baking soda or commercial buffer needed to raise KH
Aquarium CO2 Bubble Count Rate Calculator
Convert CO2 bubble count per second to an approximate dosing rate
Aquarium Flow & Turnover Rate Calculator
Calculate filter and powerhead flow needed for your tank turnover
Aquarium Heater Wattage Calculator
Size the right heater wattage for your tank and room temperature
Aquarium Live Rock Amount Calculator
Calculate pounds of live rock needed for a reef tank
Aquarium Nitrogen Cycle Tracker
Log ammonia, nitrite, and nitrate to track new-tank cycling progress
Aquarium Medication Dosing Calculator
Calculate medication dose for your exact aquarium volume
Aquarium Quarantine Tank Protocol Calculator
Calculate medication rotation schedule for a quarantine tank
Planted Tank CO2 Reactor Sizing Calculator
Size a CO2 reactor for your planted aquarium by volume and plant mass
Aquarium Salinity / Specific Gravity Converter
Convert between ppt salinity, specific gravity, and conductivity for reef tanks
Aquarium Stocking Capacity Calculator
Inch-per-gallon and surface-area stocking rules for fish tanks
Aquarium Substrate Amount Calculator
Calculate bags of gravel, sand, or aquasoil for any tank depth
Aquarium Sump Volume & Return Pump Calculator
Size your sump and return pump for any display tank
Aquarium Tank Volume Calculator
Calculate gallons and liters for any tank shape
Aquarium TDS Remineralization Calculator
Dose remineralizer to hit a target TDS for shrimp tanks
Aquarium Water Change % Calculator
Calculate how many water changes reduce a pollutant to your target level
Aquarium Substrate Depth Guide Calculator
Minimum substrate depth for live plants by plant root depth category
Garden Irrigation Deficit Calculator
Calculate supplemental watering needed after measured rainfall
Drip Irrigation Run Time Calculator
Find the run time to deliver your target water volume
Hydroponics Nutrient Solution Calculator
Mix nutrient concentrates to a target EC and ppm for hydro growing
Aquaculture Stocking Density Calculator
Calculate maximum stocking density and feed loading per pond or tank volume
Crop Yield Estimator
Estimate corn, wheat, or soybean yield from ear count, kernel count, and test weight
Fertilizer N-P-K Rate Calculator
Calculate fertilizer product quantity to supply target N, P, and K per acre
Hay Bale Weight Estimator
Estimate hay bale weight from dimensions and species for round, square, and large square bales
Irrigation Run-Time Calculator
Calculate how long to run irrigation to apply a target depth of water
Livestock Gestation Date Calculator
Calculate expected delivery date for cattle, sheep, pigs, horses, and goats
Livestock Stocking Rate Calculator
Calculate carrying capacity in AUEs from pasture area and forage yield
Silage Tonnage Calculator
Estimate fresh and dry-matter tonnes of silage in a clamp, pit, or pile
Livestock Veterinary Drug Dose Calculator
Calculate drug dosage and volume to draw for cattle, sheep, and pig treatments
Grass Seed Calculator
Work out how much lawn seed you need — and what it will cost.
Aquarium Volume Calculator
Find your tank volume in litres, US gallons and UK gallons — five shapes supported.
Garden & Raised-Bed Soil Volume Calculator
Find out exactly how many litres (or bags) of compost or topsoil your raised bed needs.
Plant Spacing Calculator
Find exactly how many plants fit your bed — square or triangular grid.
Hydroponic Nutrient Calculator
Calculate exact salt weights for any reservoir volume and EC target.
Pond Volume Calculator
Calculate pond volume, liner size, pump output, fish stocking and treatment doses.
Fertilizer NPK Calculator
Calculate nutrients delivered, required application rates, and bags needed from any NPK grade.
Seeding Rate Calculator
Calculate the exact kg/ha or lb/acre seeding rate for any crop — and back-calculate population, TSW or establishment.
Chicken Feed Calculator
Daily feed, water, and nutrient needs for any chicken type — layers, broilers, pullets, and more.
Crop Yield Calculator
Calculate yield per hectare or acre from any harvest quantity and field area.
Greenhouse Heating Calculator
Size your greenhouse heater in seconds — fabric loss, infiltration and all.
Irrigation Water Calculator
Calculate gross irrigation requirements, water volumes, and flow rates for any crop and field.
Stocking Density Calculator
Calculate animals per area or biomass per volume — with welfare band assessment.
Hay Bale Calculator
Calculate bale volume, dry matter and how many bales your livestock need.
Livestock Feed Calculator
Calculate daily feed, energy and protein requirements for cattle, sheep, pigs and poultry.
Silage Calculator
Clamp volume, field yield, DM tonnage and feeding days — all in one tool.
Home & DIY
3D Print Total Cost Per Gram
Factor electricity, machine depreciation, and failures into true print cost
3D Print Scale Factor Calculator
Find the scale percentage to resize a model to exact dimensions
3D Print Thread Sizing Chart
Find the correct hole diameter for printed internal threads (ISO, UNC, UNF)
Hot Water Boiler Output & Radiation Calculator
Match boiler net output to connected fin-tube baseboard and cast-iron EDR radiation.
Room BTU Calculator
Size a window AC, mini-split or portable unit for a room with the ENERGY STAR method
Candle Wax & Fragrance Calculator
Calculate wax and fragrance oil amounts for any candle vessel
Crochet Gauge & Stitch Count Calculator
Scale any crochet pattern for your actual gauge
Cross Stitch Fabric Count Calculator
Calculate finished size for any cross stitch pattern on any fabric count
Fabric Shrinkage Calculator
Calculate pre-washed fabric yardage needed accounting for shrinkage
Knitting Increase/Decrease Spacing Calculator
Evenly space increases or decreases over a run of rows or stitches
Knitting Blocking Dimensions Calculator
Calculate wet-blocked dimensions from dry measurements and yarn type
Knitting Gauge Converter & Stitch Calculator
Convert gauge swatches and recalculate stitch counts for any yarn
Knitting Provisional Cast-On Reference
Calculate stitch count and method for any provisional cast-on technique
Knitting Row & Round Counter
Count rows, rounds, and repeats for any knitting project
Knitting Sock Heel Turn Calculator
Calculate short-row heel or flap-and-gusset sock heel math
Lorcana Deck Consistency Score
Score Lorcana deck consistency from ink curve and card mix
Mulch / Bark Volume Calculator
Calculate cubic yards or bags of mulch for any garden area
Quilt Block Size & Fabric Calculator
Calculate finished vs unfinished block sizes and yardage
Radiant Floor Heating BTU Output Calculator
Calculate BTU/h output per square foot from radiant in-floor tubing spacing and water temperature.
Resin Print Support Angle Guide
Determine safe overhang angles without supports for resin SLA/MSLA prints
Soap Lye (Saponification) Calculator
Calculate NaOH or KOH lye amount for any soap oil recipe
Solar Panel Daily/Monthly Output Calculator
Calculate expected kWh output from a PV array by watts, sun hours, and derate.
TCG Deck Building Budget Calculator
Estimate total deck cost from card counts and single prices
Wargame Terrain & Miniature Paint Coverage Calculator
Estimate paint pots needed for any miniature or terrain project
Reptile Terrarium Humidity & Misting Calculator
Calculate misting frequency to hold your target humidity
Yarn Yardage Estimator
Calculate yarn needed for any knitting or crochet project
Brick & Block Count Calculator
Estimate bricks or blocks required for any wall area with mortar joint
Composite Deck Material Calculator
Estimate lineal feet, boards, and fasteners for a composite deck
Concrete Anchor Pullout Strength Calculator
Estimate anchor bolt tensile capacity in concrete using ACI 318 concrete breakout
Concrete Volume Calculator
Calculate concrete volume in cubic yards or cubic metres for slabs, columns, or footings
Deck Joist Span Calculator
Verify allowable joist span for any lumber size, species, and spacing
Drywall Sheet Calculator
Calculate drywall sheets, screws, tape, and mud for any room
Fetal Growth Centile Calculator (INTERGROWTH-21st)
Plot estimated fetal weight against gestational-age centiles
Floor & Wall Tile Calculator
Estimate tile count, thinset bags, and grout for any room with waste factor
Gas Appliance Total BTU/h Load Calculator
Sum gas appliance BTU/h ratings and verify meter and regulator capacity
Gravel & Aggregate Volume Calculator
Calculate cubic yards and tons of gravel, crushed stone, or sand for any area
Home Insulation Payback Calculator
Calculate payback period and CO2 savings for loft or wall insulation
Insulation R-Value Calculator
Calculate total wall or ceiling R-value from multiple insulation layers
Paint Coverage Calculator
Estimate gallons needed for any room based on coverage and coats
Pipe Insulation Heat Loss Calculator
Calculate heat loss per linear foot from bare vs insulated hot water or chilled water pipe.
Proof-of-Work Hash Demo
Interactively mine a block hash with adjustable difficulty in the browser
Roof Pitch & Rafter Length Calculator
Calculate rafter length, ridge height, and board count from span and pitch
Roofing Square & Material Calculator
Turn a roof footprint and pitch into squares, shingle bundles, and ridge cap
Solar Farm Yield Estimator for Agricultural Land
Estimate annual kWh output and agrivoltaic revenue from solar-plus-agriculture installations
PV Panel Mismatch Loss Calculator
Estimate power loss from mixing panels with different Isc or Voc in a string
Stair Stringer Calculator
Calculate rise, run, stringer length, and angle for any stair height
Roof Drain & Stormwater Pipe Sizing Calculator
Size roof drains and leader pipes from roof area and design rainfall intensity per IPC 1106.
Paint Calculator
How much paint to buy for any room — walls, coats and openings.
Tile Calculator
How many tiles to buy for a floor or wall, including waste.
Flooring Calculator
How many packs of laminate, vinyl or wood flooring to buy.
Concrete Calculator
Concrete volume and number of bags for a slab or footing.
Mulch Calculator
How much mulch, bark or compost to cover a garden bed.
Brick Calculator
Estimate how many bricks a wall needs, with a waste allowance.
Gravel Calculator
Work out the volume and weight of gravel for any area.
Fence Calculator
Count the posts, panels and rails for a fence run.
BTU Air Conditioner Calculator
Size an AC unit by working out the BTU your room needs.
Roof Pitch Calculator
Convert between rise/run, angle, percent and x-in-12 pitch.
BTU to kWh Converter
Convert BTU to kilowatt-hours and back, instantly.
Mulch & Soil Calculator
Bed size + depth → cubic yards or metres, bags needed and total cost.
Stairs Calculator
Turn total rise and run into steps, riser height, tread depth and stringer length — with building-code checks.
BTU Calculator
Size heating and cooling: room BTU plus the right air-conditioner.
Wallpaper Calculator
How many rolls of wallpaper you need — pattern repeat and cost included.
Fence and Gate Calculator
Run length, post spacing and gates to posts, panels, rails, concrete and cost.
Roof Area Calculator
Turn a building footprint and roof pitch into actual roof surface area, materials and cost.
Crushed Stone Calculator
Area, depth and material density to tonnes, bags and cost.
Asphalt Calculator
Turn area, depth and mix density into tonnes of asphalt — plus a cost estimate.
Flooring Calculator (Multi-Room, with Cost)
Packs of laminate, hardwood or vinyl across every room — plus cost and waste.
Pool Volume Calculator
Work out your pool volume in litres and gallons, plus chlorine dosing.
Brick Calculator
Wall area + brick size + mortar joint → bricks, mortar bags and cost.
Deck Building Calculator
Turn deck size into a board, joist and screw count — with a cost estimate.
Solar Panel Calculator
Size a solar array from your energy use or roof area — panels, output and savings.
Insulation Calculator
Area + target R-value + pack coverage → packs, rolls and cost.
Carpet Calculator
How much carpet to buy from a fixed-width roll — with waste, stairs and cost.
Drywall Calculator
Sheets of plasterboard, screws, compound and tape — with a cost estimate.
Paint Calculator
Wall area minus doors and windows, coats and coverage, to paint and cost.
3D Print Filament Cost Calculator
Find the exact material cost of any print from grams used and spool price.
3D Print Time & Material Estimator
Estimate print time, filament usage and material cost from model volume, infill and speed.
Board Foot Calculator
Instantly calculate board feet from lumber dimensions and get a material cost estimate.
Crochet Hook Size Converter
Instantly convert crochet hook sizes between US, UK and metric (mm).
Fabric Yardage Calculator
Enter your pattern pieces, pick a bolt width, and get the exact yardage to buy.
Knitting Gauge Calculator
Work out cast-on stitches and rows from your gauge swatch and target size.
Quilt Binding & Backing Calculator
Know exactly how much fabric to buy for binding and backing before you cut a single strip.
Resin 3D Print Cost Calculator
Find the exact material cost of any MSLA or DLP resin print from mL used and bottle price.
Yarn Yardage Calculator
Find exactly how many yards — and skeins — your knitting or crochet project needs.
Candle Wax Calculator
Work out exactly how much wax, fragrance oil and dye you need for any batch.
Epoxy Resin Calculator
Calculate exact Part A and Part B volumes for any mould shape and mix ratio.
Firewood Cord Calculator
Convert stack dimensions to full cords, face cords, BTU and seasonal cost.
Kerf Calculator
Calculate material loss from saw cuts and plan your cut list precisely.
Soap Lye Calculator
Calculate exact NaOH or KOH lye amounts for cold-process and liquid soapmaking.
Wood Shrinkage Calculator
Predict exact dimension loss as lumber dries from green to target moisture content.
Finance & Money
UK Mortgage Calculator
Work out monthly repayments, total interest and overpayment savings.
Compound Interest & Savings Calculator
Project savings growth with regular deposits and compound interest.
Free Invoice Generator
Build a branded invoice with line items, tax and totals, then export a clean PDF.
Loan & Personal Credit Calculator
Monthly payment, total cost of credit and representative APR.
Loan Comparison Tool
Compare up to 3 loans side by side — payment, total interest and a balance chart.
Tip Calculator & Bill Splitter
Split the bill, add a tip, round up and share the result.
Currency Converter
Convert between major currencies with live exchange rates.
Monthly Budget Planner
Track income and expenses, see your savings rate, and get a live spending chart.
Pakistan Salary Income Tax Calculator (FY 2024-25)
Monthly take-home after Pakistan income tax — salaried slabs for FY 2024-25.
Card Grading ROI Calculator
Calculate whether grading a card is worth the submission cost
Currency Banknote Grade Reference Tool
Look up PMG / PCGS paper money grade criteria by numeric grade
Embroidery Floss Length Calculator
Calculate skeins of floss needed for any embroidery or cross-stitch project
Flow Rate & Extrusion Multiplier Calculator
Calibrate extrusion multiplier from measured vs expected filament use
FPV Drone Link Budget Calculator
Estimate FPV video link range from transmitter power and antenna gain
HVAC Economizer Free-Cooling Hours Calculator
Estimate annual free-cooling hours and energy savings from an air-side economizer
LUFS Headroom & Peak Budget Calculator
Find the limiter ceiling needed to hit any streaming LUFS target.
Nigeria Pension Contribution Calculator
Calculate Nigerian Contributory Pension Scheme contributions.
SEER Energy Savings Calculator
Estimate annual cooling-energy savings and payback when upgrading to a higher-SEER air conditioner
Support Tip Diameter & Detachment Force Calculator
Estimate the force needed to remove SLA resin supports by tip diameter
Fly Fishing Tippet & Leader Taper Calculator
Build a custom fly leader with the right taper formula
Bail Bond Premium Calculator
Estimate bail bond premium, collateral, and agent fees from bail amount
Cargo Stowage Factor Calculator
Look up or calculate stowage factors for bulk and general cargo types
CFD & Spread-Bet Margin Requirement Calculator
Calculate CFD or spread-bet margin under ESMA and FCA leverage limits
Contract Liquidated Damages Calculator
Calculate liquidated damages accrued under delay or performance penalty clauses
Crypto Arbitrage Profit Calculator
Calculate arbitrage profit between two exchanges after fees and slippage
Crypto Break-Even Price Calculator
Calculate the price needed to break even after fees and cost basis
Crypto ROI & CAGR Calculator
Calculate return on investment and compound annual growth rate for crypto
Direct Air Capture Break-Even Calculator
Calculate the cost per tonne of CO2 removed via direct air capture at any scale
DeFi Flash Loan Cost Calculator
Calculate Aave or dYdX flash loan fee for a given borrow amount
Energy Efficiency kWh Savings Estimator
Estimate annual kWh and CO2 savings from energy efficiency upgrades
Freight Broker Margin Calculator
Calculate load revenue, carrier cost, gross margin, and net margin per load
Green Bond Framework Alignment Checker
Check a bond's framework against the ICMA Green Bond Principles 2021
Hash Rate Unit Converter & Profitability Context
Convert between H/s, KH/s, MH/s, GH/s, TH/s, PH/s, EH/s
Heat Pump Savings Calculator
Compare heat pump vs gas boiler running cost and CO2 savings
HIV Viral Load Log Reduction Calculator
Convert copies/mL to log₁₀ and assess treatment response
Late Payment Interest Calculator
Calculate statutory or contractual late-payment interest on overdue invoices
Attorney Hourly Rate Break-Even Calculator
Calculate the minimum hourly rate to cover overhead and salary for a solo firm
Post-Judgment Interest Rate Reference
Look up post-judgment interest rates for all 50 US states and federal courts
Crypto Mining Profitability Calculator
Calculate BTC or ETH-equivalent mining profit after electricity costs
MOI (Multiplicity of Infection) Calculator
Calculate virus or phage MOI and Poisson infection fraction
Oxy-Acetylene Tip Size & Pressure Chart
Pick the correct torch tip number and regulator pressures for any thickness
Partnership Profit Allocation Calculator
Allocate profit and loss to partners using guaranteed payments and ratios
Pilot Logbook Hour Tracker & Currency Calculator
Track total flight hours, night, IFR, and landings to check currency requirements
Predicted Peak Expiratory Flow Calculator
Expected PEFR from age, sex, and height using reference equations
Prejudgment Interest Calculator
Compute accrued prejudgment interest from damage date to judgment date
Promissory Note Amortization Calculator
Generate a full amortization schedule for fixed, interest-only, or balloon notes
Security Deposit Interest Calculator
Compute interest owed on residential security deposits under state statutes
Settlement Present Value Calculator
Discount a future lump-sum or structured settlement to today's dollars
Time Charter Operating Expense (TCOE) Calculator
Calculate all-in cost per ship-day from hire, bunkers, port costs, and commission
PV Energy Yield Estimator (Monthly)
Estimate monthly solar production from system kWp and bundled irradiance data
Solar Investment ROI & Cash Flow Calculator
Model 25-year solar cash flows with ITC, SRECs, financing, and rate escalation.
Fire Sprinkler Pipe Sizing Calculator (NFPA 13)
Size branch lines and cross-mains by NFPA 13 pipe-schedule head counts
Crypto Staking APY Calculator
Calculate real staking yield with compounding frequency and token price change
Corticosteroid Equivalence Converter
Convert doses between prednisolone, dexamethasone, hydrocortisone, and more
Structured Settlement Annuity Calculator
Model periodic payments, present value, and implied yield of structured settlements
Sustainability-Linked Loan KPI Calibrator
Calibrate SLL/SLB KPIs against LMA and ICMA ambition thresholds
Thyroid Function Result Interpreter
Classify TSH, free T4, and free T3 results by hypo/hyper pattern
Tree Farm Rotation & NPV Calculator
Calculate net present value of a timber rotation at different cutting ages and discount rates
UK Childcare Voucher & Tax-Free Childcare Calculator
Compare legacy childcare vouchers against Tax-Free Childcare savings
UK Pension Annual Allowance Checker
Check your UK pension annual allowance, tapering and carry-forward
US 401(k) Contribution Limit Calculator
Calculate maximum annual 401(k) contribution including catch-up
US Dependent Care FSA Tax Savings Calculator
Estimate federal, FICA and state tax savings from a dependent care FSA
US Roth IRA Eligibility & Contribution Calculator
Find your reduced Roth IRA limit from the IRS MAGI phase-out
US Schedule C Net Profit Calculator
Calculate sole-proprietor Schedule C net profit and SE tax impact
Albuquerque Comfortable Salary Calculator
Find the salary you need to live comfortably in Albuquerque.
Albuquerque Rent Affordability Calculator
Instantly check if an Albuquerque rental fits your income using local norms.
Atlanta Comfortable Salary Calculator
Find the salary you need to live comfortably in Atlanta.
Atlanta Rent Affordability Calculator
Instantly check if an Atlanta rental fits your income using local norms.
Austin Comfortable Salary Calculator
Find the salary you need to live comfortably in Austin.
Austin Rent Affordability Calculator
Instantly check if an Austin rental fits your income using local norms.
Baltimore Comfortable Salary Calculator
Find the salary you need to live comfortably in Baltimore.
Baltimore Rent Affordability Calculator
Instantly check if a Baltimore rental fits your income using local norms.
Boston Comfortable Salary Calculator
Find the salary you need to live comfortably in Boston
Boston Rent Affordability Calculator
Check if a Boston rental fits your income using local norms
Chicago Comfortable Salary Calculator
Find the salary you need to live comfortably in Chicago using local costs
Chicago Rent Affordability Calculator
Check if a Chicago rental fits your income using the local 30% rule
Currency Minor Unit Converter
Convert between currency major units and smallest minor units using ISO 4217 exponents.
Denver Comfortable Salary Calculator
Find the salary you need to live comfortably in Denver.
Denver Rent Affordability Calculator
Check if a Denver rental fits your income using the local 30% rule
Detroit Comfortable Salary Calculator — 50/30/20 Rule
Find the gross salary you need to live comfortably in Detroit using local rent, transit, and the 50/30/20 budget rule.
Detroit Commute Cost Calculator
Compare the true monthly cost of a Detroit commute — transit vs driving
Detroit Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Detroit
Detroit Rent Affordability Calculator — 30% Rule & Local Norms
Instantly check if a Detroit rental fits your income using the 30% rule and the local 1-BR median.
Houston Comfortable Salary Calculator
Find the salary you need to live comfortably in Houston.
Houston Rent Affordability Calculator
Check if a Houston rental fits your income using the local 30% rule.
Las Vegas Comfortable Salary Calculator
Find the salary you need to live comfortably in Las Vegas
Las Vegas Rent Affordability Calculator
Instantly check if a Las Vegas rental fits your income using local norms
Los Angeles Comfortable Salary Calculator — 50/30/20 Rule
Find the salary you need to live comfortably in Los Angeles.
Los Angeles Rent Affordability Calculator — 30% Rule
Instantly check if a Los Angeles rental fits your income using local norms.
Louisville Comfortable Salary Calculator
Find the salary you need to live comfortably in Louisville.
Louisville Rent Affordability Calculator
Instantly check if a Louisville rental fits your income using local norms.
Miami Comfortable Salary Calculator
Find the salary you need to live comfortably in Miami.
Miami Rent Affordability Calculator
Instantly check if a Miami rental fits your income using local norms.
Milwaukee Comfortable Salary Calculator
Find the salary you need to live comfortably in Milwaukee
Milwaukee Rent Affordability Calculator
Instantly check if a Milwaukee rental fits your income using local norms
Minneapolis Comfortable Salary Calculator
Find the salary you need to live comfortably in Minneapolis.
Minneapolis Rent Affordability Calculator
Instantly check if a Minneapolis rental fits your income using local norms.
Nashville Comfortable Salary Calculator
Find the salary you need to live comfortably in Nashville.
Nashville Rent Affordability Calculator
Check if a Nashville rental fits your income using local norms.
New York City Comfortable Salary Calculator
Find the salary you need to live comfortably in New York City.
New York City Rent Affordability Calculator
Check if a New York City rental fits your income using local norms.
Philadelphia Comfortable Salary Calculator
Find the salary you need to live comfortably in Philadelphia
Philadelphia Rent Affordability Calculator
Instantly check if a Philadelphia rental fits your income using local norms
Phoenix Comfortable Salary Calculator
Find the salary you need to live comfortably in Phoenix
Phoenix Rent Affordability Calculator
Instantly check if a Phoenix rental fits your income using local norms
Portland Comfortable Salary Calculator
Find the salary you need to live comfortably in Portland, Oregon
Portland Rent Affordability Calculator
Check if a Portland rental fits your income using the 30% rule
San Antonio Comfortable Salary Calculator
Find the salary you need to live comfortably in San Antonio.
San Antonio Rent Affordability Calculator
Instantly check if a San Antonio rental fits your income using local norms.
San Diego Comfortable Salary Calculator
Find the salary you need to live comfortably in San Diego
San Diego Rent Affordability Calculator
Check if a San Diego rental fits your income using the 30% rule
San Francisco Comfortable Salary Calculator
Find the salary you need to live comfortably in San Francisco
San Francisco Rent Affordability Calculator
Check if a San Francisco rental fits your income using the 30% rule
San Jose Comfortable Salary Calculator
Find the salary you need to live comfortably in San Jose
San Jose Rent Affordability Calculator
Check if a San Jose rental fits your income using local norms
Seattle Comfortable Salary Calculator
Find the salary you need to live comfortably in Seattle
Seattle Rent Affordability Calculator
Check if a Seattle rental fits your income using the 30% rule
Tucson Rent Affordability Calculator
Instantly check if a Tucson rental fits your income using local norms.
Savings Goal Calculator
How much to save each month — or how long it takes.
ROI Calculator
Return on investment, net gain and annualised ROI.
Debt Snowball Calculator
See how fast extra payments clear your debts — snowball or avalanche.
Markup vs Margin Calculator
Convert between cost, price, markup and profit margin instantly.
Net Worth Calculator
Add up your assets and liabilities to find your net worth.
UAE Emirates ID Decoder & Validator
Decode a 15-digit Emirates ID — country prefix, birth year and Luhn check digit.
Simple Interest Calculator
Work out simple interest and the total amount on a deposit or loan.
APR Calculator
Find the true annual cost of a loan once fees are included.
Mortgage Overpayment Calculator
See how much interest and time a regular overpayment saves.
Loan Comparison Calculator
Compare two loans side by side to find the cheaper overall deal.
Salary to Hourly Converter
Convert pay between hourly, weekly, monthly and yearly in one place.
Future Value Calculator
Project the future value of savings with regular contributions and compounding.
Debt Avalanche Calculator
Pay off debt fastest — avalanche vs snowball, with a payoff order.
Investment Return Calculator
Project the future value of an investment with regular contributions.
Mortgage Affordability Calculator
See how much home you can afford from your income and deposit.
Amortization Schedule Generator
Full month-by-month payment breakdown for any loan.
Salary Raise Calculator
Turn a raise percentage into real money — after inflation.
Hourly to Annual Salary Calculator
Convert an hourly rate into yearly, monthly and weekly pay.
Sales Commission Calculator
Work out commission earnings from sales and rate — instantly.
Split Bill with Tax and Tip
Split a restaurant bill evenly including tax and tip.
Freelance Rate Calculator
Work out the hourly rate a freelancer needs to charge.
Debt Payoff Planner (Snowball vs Avalanche)
List your debts, compare snowball and avalanche, and see your debt-free date on a chart.
50/30/20 Budget Calculator
Split your take-home pay into needs, wants and savings.
Savings Rate Calculator
Find your savings rate and a rough years-to-FI estimate.
Refinance Break-Even Calculator
Find how long until a refinance pays for itself.
Mortgage Points Calculator
See if buying discount points is worth the up-front cost.
Coast FIRE Calculator
Find the portfolio you need today to coast to retirement.
Money Counter
Add up cash by counting notes and coins.
Expense Tracker
Log spending by category, see monthly totals and a category chart, then export to CSV.
Investment Scenario Comparison
Compare lump-sum, dollar-cost averaging and a mixed strategy side by side.
Tip Per Person Table
One bill and tip — see each person's share for any group size.
Salary Negotiation Modeler
Compare job offers side by side — base, bonus, equity and benefits as one total-comp number.
Savings Goal Tracker
Track multiple savings goals with progress bars and a projection chart.
Gross Rent Multiplier Calculator
Price relative to gross annual rent.
Coast FIRE Calculator (Pro)
See if your pot can coast to retirement, with a year-by-year chart.
Mortgage Overpayment Scenarios
Compare three overpayment strategies side by side on one mortgage.
Event Budget Planner
Plan event costs by category, track vendors and paid status, see the spend breakdown.
Net Worth Tracker
Log assets and liabilities over time and watch your net worth trend.
Debt-Free Date Calculator
See exactly when you'll be debt-free and how much interest you'll pay.
Group Expense Splitter
Add people and shared expenses, then see exactly who owes whom.
Savings Challenge Tracker
Run a 52-week or custom savings challenge, tick off weeks and watch your total grow.
Budget Forecaster
Turn recurring income and expenses into a 12-month projected balance chart.
Amortization Schedule Calculator
Loan amount, rate and term to a full month-by-month principal and interest table.
Invoice Tracker
Track who owes you, what is overdue, and your total outstanding — exportable to CSV.
Wedding Budget Planner
Track estimated vs actual costs, payments and your target — all in your browser.
Debt Snowball Tracker
Plan your debt payoff, compare snowball vs avalanche, and see the date you go debt-free.
Road Trip Cost Splitter
Plan a multi-leg road trip, total fuel, tolls and parking, then split fairly.
Freelance Project Quote Builder
Turn hours and rates into a polished client quote with deposit terms.
Sinking Fund Planner
Plan multiple savings goals and see exactly how much to set aside each month.
Multiplication Table Generator
Make printable times-table charts and blank practice worksheets, then export to PDF.
Car Loan Calculator
Monthly payment, total interest and a full schedule from price, deposit, trade-in, APR, term, fees and tax.
401(k) Calculator
Project your retirement balance from salary, contribution rate, employer match and returns.
CAGR Calculator
Compound annual growth rate from a beginning and ending value.
Dividend Yield Calculator
Turn a share price and dividend into yield %, annual income and yield-on-cost.
FIRE Number Calculator
Find your financial-independence target and how many years until you reach it.
Home Affordability Calculator
How much house can you afford? Income, debts and deposit to a max price.
Inflation Calculator
Convert money between two years and see how inflation erodes its buying power.
Markup Calculator
Turn cost and markup into selling price, profit, and margin — or work it backwards.
Roth IRA Calculator
Project your tax-free retirement balance from contributions, years and return.
Rule of 72 Calculator
How long money takes to double — or the rate needed.
Break-Even Calculator
Find how many units you must sell to cover your costs — with a chart.
Profit Margin Calculator
Cost and price to gross margin, markup, profit and break-even — with reverse solve.
Rent Affordability Calculator
Income, the 30% rule and your expenses — your recommended maximum rent.
Emergency Fund Calculator
Size your safety net and get a month-by-month plan to reach it.
Annuity Calculator
Calculate present value, future value, or periodic payment for any annuity.
Bond Price Calculator
Price a bond from its yield — or back-solve the YTM from a market price.
Bond Yield Calculator
Calculate YTM, bond price, duration, convexity and DV01 instantly.
Gross Profit Calculator
Calculate gross profit, gross margin %, and COGS ratio across multiple periods or product lines.
IRR Calculator
Find the Internal Rate of Return for any series of cash flows — instantly.
NPV Calculator
Calculate Net Present Value, IRR, payback period and a full discounted cash-flow schedule.
Perpetuity Calculator
Price any infinite stream of payments — ordinary, growing, or deferred.
Present Value Calculator
Discount any cash flow stream to today: lump sum, annuity, growing annuity, perpetuity.
Conversions & Units
Unit Converter
Convert length, weight, temperature, volume, area and speed instantly.
Subject Distance & Angle of View Calculator
Find the distance needed to frame a subject of known size
Arc Flash Incident Energy & Boundary Calculator
Estimate arc flash incident energy and the arc-flash boundary using the IEEE 1584 Lee method
Balloon Helium Volume Calculator
Calculate helium tank size needed for a balloon decoration arch or column
Bed Tramming Angle Calculator
Calculate bed tilt angle and the knob turns needed from corner probe data
Beer Dissolved CO2 & Degassing Calculator
Calculate CO2 dissolved in beer at any temperature and pressure
Mash Enzyme Activity Temperature Guide
Find optimal temperature ranges for alpha and beta amylase activity
Camera Motion Blur & Shutter Speed Threshold Calculator
Find the slowest hand-held shutter speed before camera shake blurs the shot
Flash Sync Speed & HSS Calculator
Determine if High Speed Sync is needed and estimate HSS power loss
CO2 Regulator Pressure Guide
Interpret high and low gauge readings and estimate remaining CO2 in the tank
CO2 Tank Pressure vs Temperature Chart
Find expected CO2 tank pressure at any storage temperature
Decoction Volume Calculator
Work out how much mash to pull and boil to step up to the next rest.
Drainage Fixture Unit (DFU) Calculator
Total drainage fixture units and size horizontal drains and stacks per IPC Table 709.1
Enclosure Temperature Calculator
Estimate required enclosure temperature to prevent ABS/ASA/PC warping
EQ Bandwidth to Q Factor Converter
Convert between octave bandwidth and Q factor for parametric EQ.
FDM Bridging Distance Limit Calculator
Estimate the longest unsupported bridge a material and cooling can span
Fermentation Temperature Effect on FG
Estimate how fermentation temperature shifts final gravity and ester production
Filament Drying Time & Temperature Calculator
Get the right drying temperature and duration for wet 3D printing filament
Filament Length to Weight Converter
Convert between filament length in meters and weight in grams
Bass Length-to-Weight Calculator
Estimate largemouth and smallmouth bass weight from a measurement
Fish Weight Estimator by Length & Species
Estimate live fish weight from length using species formulas
Fishing Barometric Pressure Activity Predictor
Predict fish activity levels from barometric pressure and trend
Focal Length Equivalence Table
Compare focal lengths across full-frame, APS-C, MFT, and medium format
EQ Frequency to Note Name Converter
See which musical note corresponds to any EQ frequency band
Gas Pressure Regulator Sizing Calculator
Size first-stage and second-stage gas regulators from total BTU/h demand and inlet pressure.
Hop AAU (Alpha Acid Units) Calculator
Calculate AAU and HBU from hop weight and alpha acid percentage
Hunting Harvest Field-Dress Weight Calculator
Estimate field-dressed and edible meat yield of harvested deer or elk
Makeup Air Unit (MAU) CFM Calculator
Size makeup air CFM to replace exhaust and hold building pressurization
Refrigerant Pressure-Temperature (PT) Chart
Look up saturation temperature from gauge pressure for R-22, R-410A, R-32, R-134a, R-404A, R-407C, R-454B
Hydrometer Temperature Correction
Correct hydrometer gravity readings taken at non-calibration temperatures.
Hz to Musical Note Converter
Identify the closest musical note and cents deviation for any frequency
Infill Density to Weight Calculator
Estimate weight increase from different infill percentages for a given print
Lacto Pitch Temperature Calculator
Find optimal Lactobacillus pitch temperature for sour beer production
Macramé Cord Length Calculator
Calculate working cord lengths for any macramé project
MIDI Note Number Converter
Convert between MIDI note numbers, note names, and Hz frequencies
Miniature Scale Converter
Convert real-world dimensions to any miniature scale (28mm, 1/72, HO, N)
Nozzle Temperature by Material Lookup
Find recommended nozzle and bed temperatures for any 3D printing material
Pet Medication Weight-Based Dosing Calculator
Calculate medicine doses for dogs and cats by weight
Color Temperature & White Balance Calculator
Convert between Kelvin, Mired shift, and white balance preset names
Pipe Flow Velocity & Pressure Drop Calculator
Find flow velocity and Hazen-Williams friction loss for copper, PVC, CPVC, and steel pipe.
Plato / Brix / Specific Gravity Converter
Instantly convert between °Plato, Brix, and specific gravity
Bass Reflex Port Length Calculator
Calculate port tube length for a target tuning frequency
Pottery Clay Weight Calculator
Calculate clay needed for any wheel-thrown or hand-built piece
Print Bed PID Temperature Calculator
Estimate PID parameters for stable print bed temperature control.
Print Orientation & Support Volume Estimator
Compare support volume and print time across different print orientations.
Print Speed vs Quality Tradeoff Calculator
Find the max FDM speed before quality drops for your printer and material
Raised Bed Soil Volume Calculator
Calculate bags or cubic yards of soil for any raised bed
RC Helicopter Blade Pitch & Head Speed Calculator
Find the gear ratio, head speed, and collective pitch for your RC heli
RC Servo Torque & Horn Length Calculator
Calculate required servo torque for any control surface or mechanism
Resin Print Cost & Volume Calculator
Calculate resin cost and volume needed for SLA/MSLA prints
Retraction Distance & Speed Calculator
Get starting retraction values for your printer type and filament
Solar PPFD & DLI Outdoor Garden Calculator
Convert outdoor sun hours to DLI for plant light requirements
Sparge Water Volume Calculator
Work out how much sparge water you need to hit your pre-boil volume.
HVAC Static Pressure Drop Calculator
Sum total external static pressure across filter, coil, ducts and grilles for blower selection
Strike Water Temperature Calculator
Find the exact strike water temp to hit your target mash temperature
Support Material Weight Estimator
Estimate support structure filament weight and cost for complex prints
Temperature Correction Derating Calculator (NEC 310.15)
Derate conductor ampacity for ambient temperatures above 30 °C using NEC correction factors
Time-Lapse Interval & Clip Length Calculator
Calculate shooting interval and total shots for any time-lapse video
A=432 Hz Tuning Converter
Calculate note frequencies in A=432 Hz versus standard A=440 Hz tuning
Volumetric Flow Rate Calculator
Find maximum volumetric throughput for your hotend and filament
Brew Day Water Loss Calculator
Account for every water loss so you hit your target fermenter volume.
Sound Wavelength Calculator
Find the wavelength of any sound frequency in air or water.
Wort Gravity Units & Sugar Content Calculator
Convert specific gravity to gravity points, degrees Plato, and dissolved sugar per litre.
Absorbance ↔ Transmittance / % Transmittance Converter
Convert between A, T, and %T for any spectrophotometer reading
Adjusted Body Weight Calculator
ABW for obese patients when IBW undershoots actual weight
Aircraft CG Envelope Check Tool
Compute loaded weight and CG, then check against a generic GA aircraft envelope
Axle Weight & Load Distribution Calculator
Check axle weight compliance for a loaded semi-truck configuration
Braden Scale for Pressure Injury Risk
Six-domain pressure ulcer risk assessment for hospitalised patients
Brooder Temperature Guide for Chicks
Calculate recommended brooder temperature by week of age for layer and broiler chicks
Building Energy Performance Rating Estimator (EPC/DEC)
Estimate a building's energy rating band from consumption and floor area
Air Freight Chargeable Weight Calculator
Determine air freight chargeable weight using IATA volumetric divisor 6000
Cholesterol Unit Converter (mg/dL to mmol/L)
Convert cholesterol and lipid values across unit systems
Dimensional Weight Calculator
Calculate billed DIM weight for FedEx, UPS, DHL, and USPS using carrier divisors
Dovetail Angle & Layout Calculator
Calculate pin-to-tail ratio, angles, and baseline spacing for hand-cut dovetails
Drill Point Angle Calculator
Determine drill-point cone depth and geometry for any angle and diameter
Drug Dose by Weight Calculator
Calculate weight-based drug doses in mg/kg or mcg/kg for any patient
ENERGY STAR Compliance Qualification Checker
Check if your product category qualifies for ENERGY STAR certification
Enzyme Unit Activity Calculator
Calculate enzyme units (U/mL and U/mg) from a spectrophotometric assay
Estimated Blood Volume Calculator
Estimate total blood volume from weight and patient type
Feeds & Speeds Calculator
Calculate optimal feed rate from chip load, flutes, and spindle RPM
Fuel Economy by Trip Calculator
Calculate actual MPG, fuel cost, and CO2 from any trip distance and fill-up
Fuel Gas Pressure Drop Calculator (NFPA 54)
Verify pressure drop through a gas run stays within 0.3 in WC for low-pressure systems.
Gas Fee gwei → USD Converter
Convert Ethereum gas fees from gwei to USD and ETH in real time
Gel Loading Volume Calculator
Calculate sample and loading dye volumes for agarose gel electrophoresis
Blood Glucose Unit Converter (mg/dL to mmol/L)
Instantly convert blood glucose between mg/dL and mmol/L
Grain Test Weight & Moisture Corrector
Adjust grain test weight and bushel weight to standard moisture for marketing
Haematocrit ↔ Haemoglobin Converter
Estimate Hb from HCT or HCT from Hb using the rule of three
Heparin Weight-Based Dosing Protocol
Bolus and infusion rates for unfractionated heparin by weight
Home Energy CO2 Calculator
Estimate your household's annual carbon footprint from energy use
Evaporator / Condenser Coil Airside Pressure Drop Calculator
Estimate coil pressure drop in inches WC from face velocity and coil rows
Duct Fitting Equivalent Length Calculator
Convert elbows, tees, and diffusers to equivalent straight duct for friction sizing
Ideal Body Weight Calculator (Devine & Robinson)
Calculate IBW for drug dosing and ventilator management
ISA Temperature & Deviation Calculator
Find the standard ISA temperature at altitude and your ISA deviation
Container VGM (Verified Gross Mass) Calculator
Calculate and document container VGM per SOLAS regulation for export declarations
ISO 50001 Energy Management Readiness Checker
Self-assess ISO 50001 energy management system readiness before certification
Temperature Unit Converter (°C / °F / K)
Instantly convert between Celsius, Fahrenheit, and Kelvin
Metal Weight by Shape Calculator
Calculate weight of steel, aluminum, or brass for round, square, hex, or flat bar
Oral Morphine to Fentanyl Patch Converter
Convert daily oral morphine to a transdermal fentanyl patch strength
Mortar Mix & Volume Calculator
Calculate bags of mortar or dry-mix components for any masonry job
Nasogastric Tube Insertion Length Estimator
Estimate NG tube insertion depth from height as a placement starting point
Opioid MME Converter (Morphine Milligram Equivalents)
Convert any opioid dose to morphine equivalents for safe comparison
Paediatric Tidal Volume & Ventilator Settings Calculator
Weight-based ventilator tidal volume for lung-protective ventilation
Parcel Cost-Per-Unit Calculator
Compare shipping cost per unit across different parcel pack configurations
PCR Annealing Temperature Optimizer
Suggest an annealing temperature from primer pair Tm values
Pediatric Weight-Based Dosing Calculator
Safe peds drug doses with weight and max-dose guardrails
Pipe Schedule & Pressure Rating Calculator
Find pipe wall thickness, weight, and working pressure for any schedule and size
Plumbing Fitting Angle & Rolling Offset Calculator
Solve rolling offsets for pipe runs moving simultaneously horizontal and vertical.
Weld Preheat & Interpass Temperature Calculator
Calculate carbon equivalent and minimum preheat for steel per AWS D1.1
Pressure Altitude Calculator
Convert altimeter setting and indicated altitude to pressure altitude
Centrifuge RCF / RPM Converter
Convert between relative centrifugal force and revolutions per minute
Rebar Weight Calculator
Calculate total rebar weight for any bar size, count, and length
Refrigerant System Charge Weight Calculator
Estimate total refrigerant charge from line length and component charges
Refrigerant Leak-Check Nitrogen Pressure Calculator
Find the safe dry-nitrogen leak-test pressure for an HVAC system by refrigerant MAWP
Renewable Energy Certificate (REC/REGO) Cost Calculator
Calculate the cost of matching electricity use with RECs, GOs, or REGOs
Router Bit Speed Calculator
Find the safe RPM range for any router bit diameter to avoid over-speed
Satoshi / Wei / Gwei Unit Converter
Convert between BTC (satoshi, mBTC, BTC) and ETH (wei, gwei, ether) units
Floor Screed Volume Calculator
Calculate sand and cement screed volume plus mix quantities for any floor
Ship ETA / Speed / Time Calculator
Solve for ETA, required speed, or voyage time given any two of three variables
Shipping Emissions Calculator
Calculate CO2e per tonne-km across sea, air, rail, and road freight
Parcel Shipping Zone Calculator
Determine the UPS, FedEx, or USPS zone from origin and destination ZIPs
Sickle Cell Exchange Transfusion Volume Calculator
Calculate RBC exchange volume for HbS% reduction targets
Solana Compute Unit & Priority Fee Estimator
Estimate Solana transaction compute units and the optimal priority fee
Solar Self-Consumption vs. Export Calculator
Model hourly solar vs. load to estimate self-consumption rate and grid export
Sheet Metal Spring-Back Angle Calculator
Estimate the over-bend needed to compensate for spring-back in sheet metal
Structural Steel Beam Weight Calculator
Calculate weight of W, S, HP, C, MC, L, WT, and HSS sections by piece or total order
Tank Volume Calculator
Calculate the volume of cylindrical, rectangular, conical, and spherical tanks in gallons and liters.
Tapping Torque Calculator
Estimate tap torque and check against material/tap-size limits to prevent breakage
Thread Engagement Length Calculator
Calculate minimum thread engagement depth to prevent strip-out in any material
Token Unlock Selling Pressure Estimator
Estimate sell pressure from upcoming token unlocks vs daily volume
Commercial Plumbing Fixture Count Calculator (IPC 403)
Find minimum water closets, urinals, and lavatories required for an occupancy type per IPC.
V-Speeds Reference & Explanation Tool
Look up V-speed definitions, typical values, and use cases for GA aircraft
Vessel Deadweight Utilisation Calculator
Calculate payload, deadweight utilisation, and intake from draft and constants
Vessel Speed-Fuel Optimisation Calculator
Find the speed that minimises total voyage cost including fuel and hire over a fixed distance
Water Pressure Reducing Valve (PRV) Setting Calculator
Set PRV pressure for elevation change and stay within IPC code limits
Aircraft Weight & Balance Calculator
Check that loaded weight and CG stay within limits across your stations
Weld Bead Volume & Filler Metal Weight
Estimate filler metal consumption in kg or lb for any weld joint cross-section
Wind Correction Angle Calculator
Solve the E6B wind triangle for heading and groundspeed in a crosswind
Wire Pulling Tension & Sidewall Pressure Calculator
Check pulling tension and sidewall bearing pressure for large cable pulls per NEMA WC 74.
Overhead Wire Sag & Tension Calculator
Calculate sag and tension for overhead conductors at a given span and temperature
Byte and Bit Size Converter
Convert between bits, bytes, KB, MB, GB, TB in both IEC and SI units
Chinese Sexagenary Cycle Converter
Find the Heavenly Stem and Earthly Branch for any Gregorian year
Countdown Target Date Converter
Convert a future date into a live countdown in days, hours, and minutes
Gregorian ↔ Julian Calendar Converter
Convert dates between the Gregorian and old Julian calendar
Gregorian ↔ Hebrew Date Converter
Convert calendar dates to/from the Hebrew lunisolar calendar
Gregorian ↔ Hijri Date Converter
Convert between Gregorian and Islamic Hijri calendar dates
Julian Day Number Converter
Convert Gregorian dates to and from integer Julian Day Numbers
Mayan Numeral Converter
Represent any integer using the Mayan vigesimal (base-20) dot-and-bar system.
Number to Ordinal Converter
Append ordinal suffixes: 1st, 2nd, 3rd, 4th…
Number to Words Converter
Spell out any integer in English words (one, two, three…)
Sidereal Time Calculator
Compute Greenwich and local sidereal time for astronomy and telescope alignment
12-Hour and 24-Hour Time Converter
Convert times between 12-hour AM/PM and 24-hour military format
Acres to Hectares Converter
Convert ac to ha instantly — 1 ac = 0.4046856422 ha. Free, browser-only tool.
Acres to Square Metres Converter
Convert ac to m² instantly — 1 ac = 4046.856422 m². Free, browser-only tool.
Bar to PSI Converter
Convert bar to psi instantly — 1 bar = 14.50377378 psi. Free, browser-only tool.
Bytes to Kilobytes Converter
Convert B to KB instantly — 1 B = 0.001 KB. Free, browser-only tool.
Celsius to Fahrenheit Converter
Convert °C to °F instantly — °F = °C × 1.8 + 32. Free, browser-only tool.
Celsius to Kelvin Converter
Convert °C to K instantly — K = °C + 273.15. Free, browser-only tool.
Centimetres to Inches Converter
Convert cm to in instantly — 1 cm = 0.3937007874 in. Free, browser-only tool.
US Cups to Millilitres Converter
Convert cup to mL instantly — 1 cup = 236.5882365 mL. Free, browser-only tool.
Fahrenheit to Celsius Converter
Convert °F to °C instantly — °C = °F × 0.5555555556 − 17.77777778. Free, browser-only tool.
Feet to Metres Converter
Convert ft to m instantly — 1 ft = 0.3048 m. Free, browser-only tool.
US Gallons to Litres Converter
Convert gal to L instantly — 1 gal = 3.785411784 L. Free, browser-only tool.
Gigabytes to Terabytes Converter
Convert GB to TB instantly — 1 GB = 0.001 TB. Free, browser-only tool.
Gigabytes to Megabytes Converter
Convert GB to MB instantly — 1 GB = 1000 MB. Free, browser-only tool.
Grams to Ounces Converter
Convert g to oz instantly — 1 g = 0.03527396198 oz. Free, browser-only tool.
Hectares to Acres Converter
Convert ha to ac instantly — 1 ha = 2.471053815 ac. Free, browser-only tool.
Inches to Centimetres Converter
Convert in to cm instantly — 1 in = 2.54 cm. Free, browser-only tool.
Inches to Millimetres Converter
Convert in to mm instantly — 1 in = 25.4 mm. Free, browser-only tool.
Kilobytes to Bytes Converter
Convert KB to B instantly — 1 KB = 1000 B. Free, browser-only tool.
Kilobytes to Megabytes Converter
Convert KB to MB instantly — 1 KB = 0.001 MB. Free, browser-only tool.
Kelvin to Celsius Converter
Convert K to °C instantly — °C = K − 273.15. Free, browser-only tool.
Kilograms to Stone Converter
Convert kg to st instantly — 1 kg = 0.1574730444 st. Free, browser-only tool.
Kilograms to Pounds Converter
Convert kg to lb instantly — 1 kg = 2.204622622 lb. Free, browser-only tool.
Kilometres to Miles Converter
Convert km to mi instantly — 1 km = 0.6213711922 mi. Free, browser-only tool.
Kilometres per Hour to Knots Converter
Convert km/h to kn instantly — 1 km/h = 0.5399568035 kn. Free, browser-only tool.
Kilometres per Hour to Miles per Hour Converter
Convert km/h to mph instantly — 1 km/h = 0.6213711922 mph. Free, browser-only tool.
Knots to Kilometres per Hour Converter
Convert kn to km/h instantly — 1 kn = 1.852 km/h. Free, browser-only tool.
Pounds to Kilograms Converter
Convert lb to kg instantly — 1 lb = 0.45359237 kg. Free, browser-only tool.
Litres to US Gallons Converter
Convert L to gal instantly — 1 L = 0.2641720524 gal. Free, browser-only tool.
Litres to Millilitres Converter
Convert L to mL instantly — 1 L = 1000 mL. Free, browser-only tool.
Megabytes to Gigabytes Converter
Convert MB to GB instantly — 1 MB = 0.001 GB. Free, browser-only tool.
Megabytes to Kilobytes Converter
Convert MB to KB instantly — 1 MB = 1000 KB. Free, browser-only tool.
Metres to Feet Converter
Convert m to ft instantly — 1 m = 3.280839895 ft. Free, browser-only tool.
Miles to Kilometres Converter
Convert mi to km instantly — 1 mi = 1.609344 km. Free, browser-only tool.
Millilitres to US Cups Converter
Convert mL to cup instantly — 1 mL = 0.004226752838 cup. Free, browser-only tool.
Millilitres to Litres Converter
Convert mL to L instantly — 1 mL = 0.001 L. Free, browser-only tool.
Millimetres to Inches Converter
Convert mm to in instantly — 1 mm = 0.03937007874 in. Free, browser-only tool.
Ounces to Grams Converter
Convert oz to g instantly — 1 oz = 28.3495231 g. Free, browser-only tool.
PSI to Bar Converter
Convert psi to bar instantly — 1 psi = 0.0689475729 bar. Free, browser-only tool.
Square Feet to Square Metres Converter
Convert ft² to m² instantly — 1 ft² = 0.09290304 m². Free, browser-only tool.
Square Metres to Acres Converter
Convert m² to ac instantly — 1 m² = 0.0002471053815 ac. Free, browser-only tool.
Square Metres to Square Feet Converter
Convert m² to ft² instantly — 1 m² = 10.76391042 ft². Free, browser-only tool.
Stone to Kilograms Converter
Convert st to kg instantly — 1 st = 6.35029318 kg. Free, browser-only tool.
Terabytes to Gigabytes Converter
Convert TB to GB instantly — 1 TB = 1000 GB. Free, browser-only tool.
Area Calculator
Area of a rectangle, triangle, circle, trapezoid and more.
Volume Calculator
Volume of a box, sphere, cylinder, cone and more.
MPG to L/100km Converter
Convert miles-per-gallon to litres-per-100km and back, UK or US gallons.
Weighted Grade Calculator
Combine scores and category weights into a single weighted grade.
Julian to Gregorian Date Converter
Convert dates between the Julian and Gregorian calendars.
Hijri to Gregorian Converter
Convert an Islamic (Hijri) date to the Gregorian calendar.
Hebrew Calendar Converter
Convert a Gregorian date to the Hebrew (Jewish) calendar.
Persian (Jalali) Calendar Converter
Convert between Gregorian and Persian (Solar Hijri / Jalali) dates.
Ethiopian Calendar Converter
Convert between Gregorian and Ethiopian (Ge'ez) dates.
Thai Buddhist Date Converter (BE ⇄ CE)
Convert between Gregorian dates and the Thai Buddhist Era (พ.ศ.).
Nepali Bikram Sambat Converter (BS ⇄ AD)
Convert between Gregorian dates and the Nepali Bikram Sambat calendar.
Japanese Era Converter (Gengō / 和暦)
Convert between Gregorian dates and Japanese era years (Reiwa, Heisei…).
Coptic Calendar Converter (A.M. ⇄ Gregorian)
Convert between Gregorian dates and the Coptic calendar (Anno Martyrum).
Miles to Nautical Miles Converter
Convert mi to nmi instantly — 1 mi = 0.868976 nmi. Free, browser-only tool.
Celsius to Rankine Converter
Convert °C to °Ra instantly — °Ra = °C × 1.8 + 491.67. Free, browser-only tool.
Fahrenheit to Kelvin Converter
Convert °F to K instantly — K = (°F − 32) × 5/9 + 273.15. Free, browser-only.
Bits to Bytes Converter
Convert bits, bytes, kbit, KB, Mbit, MB, Gbit and GB — 1 byte = 8 bits.
File Size Converter
Convert B, KB, MB, GB, TB and binary KiB, MiB, GiB side by side.
Unit Price Comparison Calculator
Compare price per unit across pack sizes to find the best value.
Philippines TIN Validator
Check the structure of a Philippine tax ID number (TIN) instantly.
Grams to Kilograms Converter
Convert g to kg instantly — 1 kg = 1000 g. Free, browser-only tool.
Tonnes to Kilograms Converter
Convert t to kg instantly — 1 t = 1000 kg. Free, browser-only tool.
Yards to Meters Converter
Convert yd to m instantly — 1 yd = 0.9144 m. Free, browser-only tool.
Meters to Yards Converter
Convert m to yd instantly — 1 yd = 0.9144 m. Free, browser-only tool.
Miles to Yards Converter
Convert mi to yd instantly — 1 mi = 1760 yd. Free, browser-only tool.
Feet to Inches Converter
Convert ft to in instantly — 1 ft = 12 in. Free, browser-only tool.
Inches to Feet Converter
Convert in to ft instantly — 1 ft = 12 in. Free, browser-only tool.
Nautical Miles to Kilometers Converter
Convert nmi to km instantly — 1 nmi = 1.852 km. Free, browser-only tool.
Milliliters to Teaspoons Converter
Convert mL to US teaspoons (and back) instantly.
Milliliters to Tablespoons Converter
Convert mL to US tablespoons (and back) instantly.
Fahrenheit to Rankine Converter
Convert °F to °Ra (and back) instantly.
Square Kilometers to Square Miles Converter
Convert km² to mi² (and back) instantly.
Grams to Cups (Flour) Converter
Convert flour between grams and US cups by type.
Grams to Cups (Sugar) Converter
Convert sugar between grams and US cups by type.
Butter Converter
Convert butter between grams, ounces, cups, sticks and tablespoons.
Millilitres to Fluid Ounces Converter
Convert ml to US and UK fluid ounces, both ways.
Fuel Economy Comparison
Compare two vehicles by annual fuel cost — MPG or L/100km.
Frequency & Wavelength Calculator
Convert between frequency and wavelength for any wave.
Potential Energy Calculator
Gravitational PE = m·g·h — solve for energy, mass, or height.
Speed of Sound Calculator
Speed of sound in air at any temperature, plus travel time.
kWh to MJ Converter
Convert kilowatt-hours to megajoules and back, exactly.
Torque N·m to ft·lb Converter
Convert newton-metres to foot-pounds instantly — 1 ft·lb = 1.3558179 N·m. Free, browser-only.
Pascal to Bar Converter
Convert pascals to bar instantly — 1 bar = 100000 Pa. Free, browser-only.
Mbps to MB/s Converter
Convert internet speed in megabits to file transfer in megabytes per second.
Gbps to Mbps Converter
Convert gigabit per second link speeds to megabits per second.
Alcohol Units Calculator
UK units and US standard drinks from volume and ABV.
Rectangle Calculator
Area, perimeter and diagonal of a rectangle.
Sample Rate Converter
Find the resampling ratio between two audio sample rates.
Frame Rate Converter
Convert between video frame rates and frame counts.
Weeks to Days Converter
Convert weeks to days (and back) instantly.
Days to Hours Converter
Convert days to hours (and back) instantly.
Hours to Minutes Converter
Convert hours to minutes (and back) instantly.
Minutes to Seconds Converter
Convert minutes to seconds (and back) instantly.
Years to Months Converter
Convert years to months (and back) instantly.
Months to Weeks Converter
Convert months to weeks (and back) using the average month.
Kelvin to Fahrenheit Converter
Convert Kelvin to Fahrenheit and back.
Square Feet to Acres Converter
Convert square feet to acres and back.
Cups to Grams Rice Converter
Convert cups of rice to grams instantly — by rice type. Free, browser-only.
Tablespoons to Cups Converter
Convert tbsp to cups instantly — 1 cup = 16 tbsp. Free, browser-only tool.
US Quarts to Litres Converter
Convert qt to L instantly — 1 qt = 0.946352946 L. Free, browser-only tool.
US Pints to Millilitres Converter
Convert pt to mL instantly — 1 pt = 473.176473 mL. Free, browser-only tool.
US Gallons to Cups Converter
Convert gal to cups instantly — 1 gallon = 16 cups. Free, browser-only tool.
Fluid Ounces to Millilitres Converter
Convert fl oz to mL instantly — 1 fl oz = 29.5735 mL. Free, browser-only tool.
Water Intake by Body Weight Calculator
How much water to drink based on your weight.
Air Fryer Conversion Calculator
Convert any oven recipe to air fryer temperature and time.
Egg Size Substitution Calculator
Swap small, medium, large or jumbo eggs in any recipe.
International Shoe Size Converter
Convert shoe sizes between US, UK, EU and centimetres.
Hat Size Converter
Turn head circumference into US, UK, EU and S–XL hat sizes.
Bra Size Converter
Convert bra sizes between UK, US, EU, FR and AU/NZ.
Glove Size Converter
Convert hand circumference into numeric and S–XL glove sizes.
Belt Size Converter
Find your belt size from waist measurement in inches, cm or letters.
GPA to Letter Grade Converter
Turn a 4.0-scale GPA into its letter grade instantly.
Milligrams to Grams Converter
Convert mg to g instantly — 1 g = 1000 mg. Free, browser-only tool.
Micrograms to Milligrams Converter
Convert µg to mg instantly — 1 mg = 1000 µg. Free, browser-only tool.
Centimeters to Meters Converter
Convert cm to m instantly — 1 m = 100 cm. Free, browser-only tool.
Kilometers to Meters Converter
Convert km to m instantly — 1 km = 1000 m. Free, browser-only tool.
Millimeters to Centimeters Converter
Convert mm to cm instantly — 1 cm = 10 mm. Free, browser-only tool.
Miles per Gallon UK to US Converter
Convert fuel economy between UK and US miles per gallon.
Knots to MPH Converter
Convert knots to miles per hour, both directions.
Weekly Meal Planner and Shopping List
Plan a week of meals and auto-build a combined shopping list.
Unit Price Comparator
Compare products by price per kg, litre or item to find the best value.
PPI Calculator
Turn resolution and screen size into pixels-per-inch, dot pitch and a retina check.
Fuel Economy Converter
Convert MPG (US/UK), L/100km and km/L instantly, with a cost estimate.
Weighted Random Picker
Pick winners with custom odds — weighted, cryptographically fair, with live stats.
Power Converter
Convert watts, kilowatts, megawatts, horsepower, BTU/h and ft·lb/s.
Area Converter
Convert between mm², cm², m², hectares, km², acres, square feet and more.
Angle Converter
Convert between degrees, radians, gradians, turns, arcminutes and arcseconds.
Clothing Size Converter (US / UK / EU / IT)
Convert clothing sizes between US, UK, EU and Italian sizing for tops, dresses and jackets.
Data Storage Converter
Convert bits, bytes, KB, MB, GB, TB and PB in decimal (1000) or binary (1024) mode.
Energy Converter
Convert joules, calories, watt-hours, BTU, foot-pounds and electronvolts.
Frequency Converter
Convert Hz, kHz, MHz, GHz, RPM and period (seconds) — type any field, the rest update live.
Length Converter
Convert between mm, cm, m, km, inches, feet, yards, miles and more — live.
Pressure Converter
Convert between Pa, kPa, bar, psi, atm, mmHg, torr and inHg instantly.
Shoe Size Converter
Convert shoe sizes between US, UK, EU and CM for men, women and kids.
Speed Converter
Convert between m/s, km/h, mph, knots, ft/s and Mach instantly.
Temperature Converter
Convert Celsius, Fahrenheit, Kelvin and Rankine with exact formulas.
Time Unit Converter
Convert between nanoseconds, seconds, hours, days, weeks, months and years.
Torque Converter
Convert torque between N·m, kgf·m, lbf·ft, lbf·in and dyn·cm.
Volume Converter
Convert ml, litres, cubic metres, teaspoons, cups, pints, quarts and gallons (US and UK).
Weight & Mass Converter
Convert milligrams, grams, kilograms, tonnes, ounces, pounds, stones and tons in one live grid.
Ring Size Converter
Convert ring sizes between US, UK, EU, circumference and diameter.
Speed Distance Time Calculator
Enter any two of speed, distance, or time — instantly solve for the third.
Wavelength & Frequency Calculator
Convert wavelength, frequency and photon energy in any direction.
Julian Date Converter
Convert Gregorian dates to Julian Dates (JD, JDN, MJD) and back — instantly in your browser.
Celsius to Fahrenheit Converter
Instantly convert between °C, °F, Kelvin, Rankine and Réaumur — with formulas shown.
Kg to Pounds Converter
Instantly convert kilograms to pounds (and stones + pounds) — or reverse.
Fahrenheit to Celsius Converter
Instantly convert any temperature between °F and Celsius — with full working shown.
Grams to Ounces Converter
Instantly convert grams to ounces (and back) with the exact NIST factor.
Ounces to Grams Converter
Convert oz to g instantly — 1 oz = 28.3495 g. Free, browser-only tool.
Pounds to Kilograms Converter
Instantly convert lb to kg — decimal or stone+lb entry, full conversion grid.
Stone to Pounds Converter
Convert st to lb instantly — 1 stone = 14 pounds exactly. Free, browser-only tool.
Pounds to Stone Converter
Convert pounds to stones and pounds — with kilograms too.
Date & Time
Age Calculator
Your exact age in years, months and days — plus next-birthday countdown.
India PAN Card Decoder — Validate & Decode Your PAN
Decode every segment of an Indian PAN — holder type, name initial, and series.
Candle Container Wax Shrinkage & Top-Up Calculator
Calculate the second-pour wax amount for container candle sinkholes
Cat Age in Human Years Calculator
Convert your cat's age to the equivalent human age
CCD / CMOS Image Scale Calculator
Calculate arcseconds per pixel for your telescope and camera combo
Chicken Egg Incubation Due Date Calculator
Calculate hatch date and lockdown date for any egg species
Days of Autonomy Calculator
Find how many days a battery bank powers a load with no solar recharge.
Dog Age in Human Years Calculator
Calculate your dog's equivalent human age by breed size
Frost Date Planting Schedule Calculator
Count back from last frost date to find indoor seed-starting dates
HVAC Tonnage Calculator
Convert a BTU/h cooling load to tons of refrigeration and size equipment to the nearest half-ton
Image File Size Calculator
Estimate RAW and JPEG file size from megapixels and bit depth
Lorcana Willpower & Lore Race Calculator
Track lore progress and calculate damage for Disney Lorcana
Resin Casting Shrinkage & Mold Size Calculator
Account for resin shrinkage when designing or ordering molds
3D Print Shrinkage & Tolerance Calculator
Compensate for material shrinkage when designing tight-tolerance parts
Garden Soil Drainage Percolation Calculator
Rate soil drainage from a simple timed percolation test
Time-Lapse Storage Estimator
Calculate SD card / SSD storage needed for any time-lapse shoot
Warhammer Age of Sigmar Points Calculator
Tally AoS army list points quickly
Age-Appropriate Design Code Checker
Check your children's service against the UK Children's Code (AADC)
Beers Criteria High-Risk Drug Checker for Older Adults
Flag potentially inappropriate medications per AGS Beers Criteria
Bitcoin Halving Countdown
Calculate blocks and days until the next Bitcoin halving event
Demurrage & Detention Calculator
Calculate container demurrage and detention from free-time and daily rates
Duct Leakage Test Calculator
Calculate duct leakage from blower-door test results per ACCA Manual D and IECC 2021.
France Allocation Chômage (ARE) Calculator
Calculate French unemployment benefit (ARE) daily reference wage
Grain Storage Capacity Calculator
Calculate bushels or tonnes of grain in cylindrical bins, flat storage, and piles
Growing Degree Days (GDD) Calculator
Accumulate GDDs for corn, wheat, or soybeans to predict crop development stages
India Working Days Counter
Count working days in India excluding gazetted public holidays
Leverage Liquidation Price Calculator
Calculate liquidation price for long/short futures with cross or isolated margin
Sample Freeze-Thaw Cycle Tracker
Log and limit freeze-thaw cycles for biological sample integrity
Sea Passage Fuel Cost Calculator
Calculate voyage bunker cost at different speeds using the cube-law model
DEX Slippage Calculator
Calculate expected slippage and minimum received on DEX token swaps
UK Bank Holiday Working Days Counter
Count UK working days excluding England/Scotland/NI bank holidays
US Federal Holiday Working Days Counter
Count net working days excluding US federal holidays
Welding Amperage by Material Thickness
Estimate correct amperage for stick, MIG, or TIG welding any steel thickness
Wood Glue Coverage Calculator
Estimate glue quantity needed for any glue-up area at recommended spread rate
Next Weekday Date Calculator
Find the next Monday, Friday, or other weekday after a date
Quarter of Year Calculator
Determine which fiscal/calendar quarter a date falls in
Date Difference Calculator
Days, weeks and full calendar gap between any two dates.
Week Number Calculator
ISO 8601 and US week number for any date.
Add or Subtract Days Calculator
Add or subtract days, weeks, months or years from a date.
Day of the Week Finder
What day of the week was — or will be — any date.
Easter Date Calculator
Find the date of Easter Sunday for any year.
Age in Weeks and Days Calculator
Convert any age or date span into weeks and days.
Egypt National ID Decoder — Date of Birth, Governorate & Gender
Decode a 14-digit Egyptian National ID — century, date of birth, governorate and gender.
Age in Hijri Years Calculator
Convert your birth date to the Islamic calendar and get your age in Hijri years.
Ramadan Date Estimator
Estimate the Gregorian date Ramadan begins in any year.
Diwali Date Estimator
Find the date of Diwali (Lakshmi Puja) for any year.
Days Until a Date
Count how many days are left until any date — or how many have passed.
Weeks Between Two Dates
Count the number of weeks (and leftover days) between any two dates.
Age in Months and Days
Find an exact age in months and days from any birth date.
Next Birthday Countdown
See how many days until your next birthday and which weekday it falls on.
Dog Age Calculator
Convert your dog's age to human years by size and breed group.
Cat Age Calculator
Convert your cat's age to human years and life stage.
Days Alive Calculator
Find out exactly how many days you have been alive.
Age on Other Planets
See how old you would be on Mars, Jupiter and every other planet.
Countdown to New Year
Live countdown to midnight on 1 January in your local time.
Half-Birthday Calculator
Find your half-birthday — six months from the day you were born.
Data Cap Usage Calculator
Track data used against your monthly cap and project end-of-cycle usage.
Storage Needed Calculator
Estimate total storage for a batch of files from count and average size.
Work Days Between Dates
Count the working days between two dates, weekends excluded.
ISO Week Number Calculator
Find the ISO 8601 week number for any date.
Julian Day Number Calculator
Convert a calendar date to its Julian Day Number, JD and MJD.
Days in Month Calculator
How many days are in any month of any year?
Weekly Time Card Calculator
Add up a week of clock-in / clock-out times and breaks.
Age Gap Calculator
Find the age difference between two people.
Countdown to Christmas
Live days, hours, minutes and seconds until Christmas Day.
Countdown to Birthday
Live countdown to your next birthday from your date of birth.
Sprint Date Calculator
Generate agile sprint start and end dates from a cadence.
Mileage Log & Reimbursement Tracker
Log business trips and auto-calculate mileage reimbursement, with CSV export.
CCTV Storage Calculator
Size hard drives for a security camera system: cameras, resolution, retention.
Printable Calendar Generator
Make a clean printable PDF calendar for any month or full year.
Day of Week Calculator
Find any date's weekday, ISO week number, day-of-year and Julian Day Number — with step-by-step working.
Quarter of Year Calculator
Find which quarter any date falls in — with fiscal-year variants and progress bars.
Days Since Calculator
Find exactly how many days, weeks, months and years between any two dates.
Add Days to Date Calculator
Add or subtract any number of days from a date and see the full result instantly.
Days Until Birthday Calculator
Instantly see how many days until any birthday — with zodiac, birthstone, milestones and a live countdown.
Days Until Christmas Calculator
Exact days, sleeps, weeks and hours until Christmas Day — live, in your time zone.
Months Between Dates Calculator
Find the exact number of complete calendar months between any two dates.
Subtract Days from Date Calculator
Pick any date, enter a number of days, get the exact result instantly.
Weekly Time Card Calculator
Total your hours worked, split regular vs overtime, and calculate gross pay — all in one place.
Weeks Between Dates Calculator
Count the exact weeks (and leftover days) between any two dates instantly.
Working Hours Calculator
Add up daily shifts, subtract breaks, and compute gross pay with overtime.
Photo & Video
Audio File Size Calculator
Estimate uncompressed WAV/AIFF size from sample rate, bit depth and length.
Hyperfocal Distance Calculator
Find the hyperfocal distance for maximum depth of field at any aperture
Megapixel to Print Size Calculator
Find the largest print at your target DPI from your camera's megapixels
Hyperfocal Depth Chart Generator
Generate a complete hyperfocal distance table for every aperture and focal length
Astrophoto Depth of Field & Hyperfocal Distance
Calculate hyperfocal distance for sharp foreground & star-field shots
Download Time Calculator
Estimate how long a download takes from file size and connection speed.
Bandwidth Calculator
Estimate monthly bandwidth from page weight and visits per month.
Video File Size Calculator
Estimate a video file's size from duration and bitrate.
Audio File Size Calculator
Estimate audio file size for MP3, AAC or uncompressed WAV.
Upload Time Calculator
Estimate how long a file takes to upload at your real connection speed.
Crop Factor Calculator
Sensor size to crop factor, equivalent focal length and equivalent aperture — instant and precise.
Depth of Field Calculator
Near/far limits, hyperfocal distance, solve-for-any-variable and full aperture comparison.
Hyperfocal Distance Calculator
Focal length, aperture and sensor CoC to maximum depth of field — solve any variable.
More Calculators
Indonesia NIK (KTP) Decoder
Decode a 16-digit Indonesian NIK — province, date of birth and gender.
JAMB / Post-UTME / WAEC Aggregate Score Calculator
Work out your Nigerian university aggregate from JAMB, Post-UTME and O'level.
UK Statutory Entitlement Calculator (Maternity, Redundancy, Notice)
Work out Statutory Maternity Pay, redundancy pay and notice using 2025/26 rates.
Kenya Payslip & Net Pay Calculator (PAYE, SHIF, NSSF, Housing Levy)
Net pay after PAYE, SHIF, NSSF and the Affordable Housing Levy, explained.
Discount & Sale Price Calculator
Find the sale price, work out % off, or combine multiple stacked discounts.
Fuel Cost Calculator
Calculate trip fuel cost in miles/mpg or km/L per 100km, with cost splitting.
Brazil MEI DAS Calculator — Monthly Simples Nacional Payment (2025)
Calcule o DAS mensal do MEI por tipo de atividade — valores fixos 2025.
GPA Calculator
Calculate your GPA — US 4.0, UK Honours, or India 10-point CGPA.
Mexico RFC & CURP Decoder + ISR Net Pay Calculator (2024)
Decode your RFC or CURP and see your take-home pay after ISR — all in your browser.
ABV Calculator
Calculate alcohol by volume from original and final gravity readings
Apparent Attenuation Calculator
Measure how thoroughly your yeast fermented the available sugars from OG and FG.
Astrophotography Target Framing Calculator
Check if a deep-sky object fits your sensor's field of view
Astrophotography Mosaic Panel Calculator
Calculate panel count and grid layout for a multi-frame mosaic
Astrophotography Total Exposure Calculator
How many subs and how much total time for a target SNR
Audio Buffer Size & Latency Calculator
Convert buffer size and sample rate to round-trip audio latency in ms
Mix Bus Clip Headroom Calculator
Calculate how much headroom to leave on the mix bus for mastering
Theoretical Noise Floor by Bit Depth Calculator
Calculate the theoretical dynamic range and noise floor for any bit depth
Australia Superannuation Calculator
Calculate Australian employer super contributions at the current SG rate
Backflow Preventer Sizing & Selection Guide
Pick the right backflow assembly type by hazard degree and back-pressure or back-siphonage risk.
Ballistic Zero Range Calculator
Find the optimal zero and maximum point-blank range for your rifle.
Brew Batch Scaling Calculator
Scale any homebrew recipe up or down to a new batch volume.
Bead Count & Spacing Calculator
Calculate bead counts and spacing for bracelets, necklaces, and patterns
Beekeeping Honey Yield Estimator
Estimate honey yield from hive inspection data
Hop Bitterness Decay Calculator
Model IBU reduction over storage time and temperature for hop-forward beers
Beer Style Parameter Range Checker
Check if your OG, FG, IBU, ABV, and SRM fit the BJCP style guidelines
Board Game Auction / Trade Value Calculator
Estimate a fair trade or auction value for board games by condition
Board Game Score Sheet Generator
Digital score tracker for any board game
Box Fill Calculator (NEC 314.16)
Sum conductor, device, clamp, and fitting equivalents to verify junction/outlet box fill
Brazil INSS Contribution Calculator
Calculate Brazilian social-security (INSS) contributions
Brew Water Boiling Hardness Reducer
Calculate carbonate hardness reduction from pre-boiling brewing water
Brew Day Timeline Planner
Build a timed, step-by-step brew day schedule from your start time and step durations.
Wine Chaptalization (Sugar Addition) Calculator
Calculate the sugar needed to raise must Brix to a target potential ABV
Bullet Drop Ballistics Calculator
Calculate bullet drop and wind drift for any rifle cartridge to 1000 yards.
Bundling (Adjustment Factor) Derating Calculator (NEC 310.15(C))
Apply NEC bundling adjustment factors when more than 3 current-carrying conductors share a raceway
Busbar Ampacity Calculator
Estimate the current-carrying capacity of copper or aluminum bus bars.
Camera Angular Resolution Calculator
Find the minimum resolvable angle for a camera sensor and lens
Camera Sensor Size Comparison Tool
Compare physical sensor dimensions and crop factors across camera formats
Canada CPP Contribution Calculator
Calculate Canadian Pension Plan contributions for employee and employer
Cat Food Daily Portion Calculator
Calculate ideal daily food amount for your cat
HVAC CFM Airflow Calculator
Calculate required supply-air CFM from a room's heat load and supply-air temperature difference
Solar Charge Controller Sizing Calculator
Size an MPPT or PWM charge controller from array short-circuit current and battery voltage.
Chess Elo Rating Calculator
Calculate expected score and new Elo after chess games
Chess Performance Rating Calculator
Calculate your tournament performance rating from results
Cider ABV Calculator
Calculate the alcohol content of hard cider from juice gravity and FG.
Circuit Breaker Sizing Calculator
Size branch-circuit breakers for resistive loads, motors, and HVAC per NEC 240 and 430
3D Print Clearance & Fit Tolerance Calculator
Find the right gap for press-fit, slide-fit and loose-fit printed joints
CO2 Production During Fermentation
Estimate grams of CO2 produced and residual dissolved CO2 level
Coin Collection Insurance Value Estimator
Total your coin collection's declared value for insurance
Coin Grading Reference Tool
Look up Sheldon scale (1-70) coin grade descriptions and values
Coin Melt Value Calculator
Calculate the melt value of silver and gold coins by weight and purity
Condensate Drain Line Sizing Calculator
Size HVAC condensate drain lines by system capacity using the 0.8 GPH-per-ton rule and IMC Table 307.2.2
Parallel Conductor Sizing Calculator (NEC 310.10(H))
Size parallel sets of conductors for large feeders per the NEC 310.10(H) 1/0 AWG minimum rule
Cooling Load Quick Estimate (Rule of Thumb) Calculator
Estimate tonnage from floor area, window ratio, and climate zone — fast pre-quote sizing
Crossover Frequency Calculator
Find the cap and inductor values for a passive speaker crossover.
Dark Frame Count Optimization Calculator
How many dark frames do you actually need for calibration?
dB SPL Distance Calculator
Predict how loud a source is at a new distance using the inverse square law.
Dew Point Risk Calculator for Optics
Know if your telescope mirror or lens will dew over tonight
Dog Food Daily Portion Calculator
Calculate ideal daily food amount for your dog by weight and activity
Drum Tuning Frequency Calculator
Find target fundamental frequencies for kick, snare, and toms by genre
Dry Hop Biotransformation Window Calculator
Time dry hop additions to the active fermentation biotransformation window
Dry Hop Rate Calculator
Convert a target g/L dry hop rate into total hop weight for your batch
Equal Loudness Level Calculator
Compare how loud two frequencies sound at equal SPL using ISO 226.
Equal Temperament vs Just Intonation Comparator
Compare interval frequencies between equal temperament and just intonation.
ESC Current Rating Calculator
Size your ESC correctly for any motor and battery combination
EV Charger Load & Wiring Calculator
Size the circuit, wire, and breaker for Level 1, Level 2, or DC fast-charge EV installations.
Exposure Bracketing Calculator
Generate a bracket sequence of exposures around a base value
Exposure Value (EV) Calculator
Find equivalent exposures across aperture, shutter speed, and ISO
Eyepiece True Field of View Calculator
Calculate true field of view for any eyepiece and telescope
Fermentation CO2 Airlock Bubble Rate Interpreter
Estimate fermentation stage from airlock bubble frequency
Field of View Calculator
Calculate horizontal, vertical, and diagonal field of view for any lens and sensor
3D Print Filament Cost Calculator
Calculate material cost for any 3D print from filament price and weight
Filament Spool Remaining Calculator
Estimate grams remaining on a partly used spool from weight or coil diameter
First Layer Line Width Optimizer
Calculate optimal first-layer width and height for best bed adhesion
Fishing Bag Limit Tracker
Log your catch by species and size and track it against local bag limits.
Fishing Casting Distance Estimator
Estimate casting distance from rod length, lure weight, and line
Fishing Knot Strength Calculator
Estimate knot breaking strength as a percent of your line's test
Flash Guide Number Calculator
Calculate flash power, distance, or aperture from a guide number
Flash Power Reduction in Stops Calculator
Convert a flash power reduction (1/2, 1/4, 1/8...) into f-stops and the aperture or distance change to match it.
Fly Line Trolling Depth Calculator
Find the depth of a sinking fly line at any sink time and speed
Fly Tying Hook Size & Hatch Match Reference
Match hook size to natural insect size for tying flies
Focus Breathing Compensation Calculator
Estimate focal length shift from focus breathing at any distance
Focus Peaking Contrast Threshold Guide
Select the right focus peaking sensitivity level for your aperture and subject
FPV Video Frequency Channel Planner
Plan FPV frequencies to avoid interference at a flying session
France Cotisations Sociales Calculator
Estimate employee-side French social contributions on gross salary
Companion Planting Reference Tool
Look up companion and antagonist plant pairings for your garden
Generator Fuel Runtime Calculator
Estimate how long a gasoline, diesel, or propane generator runs on a given fuel quantity.
Germany Social Insurance Calculator
Calculate German Kranken-, Pflege-, Renten- and Arbeitslosenversicherung
Grain Bill Color & OG Optimizer
Adjust a two-malt grain bill to hit both your target OG and SRM colour
Gravity Points Per Pound Calculator
Predict your original gravity from grain weight, extract potential, and efficiency.
Ground Fault Loop Impedance Calculator
Verify that fault current through the EGC is enough to trip the breaker in time.
Grow Light PPFD & DLI Calculator
Calculate PPFD and daily light integral for any grow light setup
Grow Tent Ventilation & CFM Calculator
Size an inline extraction fan for your grow tent in CFM
Harmonic Derating (K-Factor) Calculator
Calculate transformer K-factor from a harmonic current spectrum to select a K-rated transformer
Harmonic Series Calculator
Generate the harmonic series (overtones) above any fundamental frequency
Knit Hat Sizing Calculator
Calculate cast-on and decrease rounds for any head size
Heat Pump Balance Point Calculator
Find the outdoor temp where heat pump capacity equals building heat loss for backup staging
Heat-Set Insert Hole Size Calculator
Get the correct boss hole diameter for heat-set threaded inserts
Hop Substitution AA% Adjuster
Adjust hop weight when swapping varieties so the bitterness stays the same.
Hunting BDC Reticle Holdover Calculator
Calculate which BDC reticle subtension to use at any hunting distance
Supply Grille/Diffuser Velocity & CFM Calculator
Calculate CFM from neck velocity and grille area, or find velocity from CFM and neck size
IBU Rager Calculator
Calculate hop bitterness using the Rager utilization formula
IBU Tinseth Calculator
Calculate International Bitterness Units using the Tinseth formula
India EPF Contribution Calculator
Calculate EPF employee and employer provident fund contributions for Indian payroll.
Inverter Sizing Calculator
Size a solar or battery inverter from continuous load watts plus motor starting surge.
Dual Native ISO Equivalence Calculator
Find equivalent exposures across a camera's dual native ISO base values
Japan Shakai Hoken Calculator
Calculate Japanese health, pension, and employment insurance contributions
Kenya NHIF Contribution Calculator
Calculate Kenyan NHIF monthly health contributions by salary band.
Kenya NSSF Contribution Calculator
Calculate Kenyan NSSF pension contributions under the 2024 NSSF Act.
Layer Height vs Print Quality Analyzer
Compare layer height options against nozzle diameter and print quality
Lens Breathing Compensation for Video
Calculate digital zoom compensation to counteract focus breathing in video
Astrophotography Light Pollution Exposure Calculator
Calculate the optimal sub-exposure for your sky's light pollution
Lighting Circuit Load Calculator
Calculate the number of lighting fixtures per 15 A or 20 A circuit using the 80% continuous-load rule
Visual Limiting Magnitude Calculator
Estimate the faintest visible star with any telescope aperture
LiPo C-Rating & Max Burst Current Calculator
Find safe continuous and burst current limits for any LiPo pack
LiPo Charge Time Calculator
Estimate charge time for any LiPo battery and charger combination
Long Exposure Noise & Hot Pixel Estimator
Predict noise level for long exposures based on sensor temperature and ISO
Lorcana Ink Curve Analyzer
Visualize and optimize your Lorcana ink curve
Malaysia EPF Contribution Calculator
Calculate Malaysian EPF (KWSP) contributions by age and salary band.
All-Grain to Extract Conversion Calculator
Convert all-grain base malt amounts into equivalent DME or LME weights.
Simplified Manual J Heat Load Calculator
Estimate residential heating and cooling loads for equipment sizing room-by-room
Mexico IMSS Contribution Calculator
Calculate Mexican social-security (IMSS) employee and employer shares
Microphone Self-Noise & SNR Calculator
Calculate microphone SNR and minimum detectable SPL from spec-sheet values
Mini-Split Ductless System Sizing Calculator
Size a single-zone or multi-zone ductless mini-split from room areas, climate zone, and construction
Gain Staging Calculator for Mixing
Track signal level and headroom at every stage of your chain
MOA / MIL Scope Adjustment Calculator
Convert bullet impact error to scope clicks in MOA or MRAD.
Motor Disconnect Switch Sizing Calculator
Size motor branch-circuit disconnect switches per NEC 430.109 and 430.110 requirements.
Motor Overload (OL) Heater Sizing Calculator
Size motor overload protection from FLA, service factor, and temperature rating per NEC 430.32.
Motor Starting (LRA) Current Calculator
Estimate locked-rotor amperes and starting kVA for AC induction motors by NEMA code letter.
ND Filter Exposure Calculator
Calculate the long-exposure shutter speed needed with ND filters
NEC 310.16 Full Ampacity Table Lookup
Searchable NEC 310.16 conductor ampacity table for copper and aluminum at 60/75/90 °C
NEC Demand Factor Calculator
Apply NEC Article 220 demand factors to reduce calculated load for services and feeders.
NEC GFCI/AFCI Requirement Checker
Look up 2023 NEC GFCI and AFCI protection requirements by room type and circuit voltage
Net Metering Payback Period Calculator
Estimate solar payback period and 25-year ROI from net-metering credits and system cost
Neutral Conductor Sizing Calculator
Size neutral conductors using NEC 220.61 demand reduction and harmonic-load rules.
Nozzle Material Wear Life Estimator
Estimate brass nozzle wear life from abrasive filament use hours
NPF Rule Star Trail Calculator
Max shutter speed before star trailing with the accurate NPF rule
Off-Grid Load Audit Calculator
Total your daily watt-hours from appliance wattage and runtime for off-grid solar design.
OG/FG/ABV Advanced Calculator
Full original gravity, final gravity, and ABV with attenuation metrics
Beer Freshness Window Calculator
Estimate shelf life and freshness windows by style and packaging method
Panorama Nodal Point Calculator
Find the no-parallax point for stitched panorama photography
Parti-Gyle Gravity Calculator
Split runnings into multiple beers and predict each runnings' gravity
Pathfinder 2e Point Buy Calculator
Build Pathfinder 2e characters with ability boosts and flaws
Pellet to Whole Hop Conversion
Convert hop weights between pellet and whole/plug hop formats
Pet Vaccination Schedule Calculator
Generate a puppy or kitten vaccine and booster schedule
Phantom Power Cable Resistance Drop Calculator
Estimate phantom power voltage drop across XLR cable resistance
Zone System Exposure Calculator
Apply Ansel Adams' Zone System to place tones for black-and-white photography
Full EV Reference Table
Browse all exposure value combinations for ISO 100 across lighting conditions
Water Supply Pipe Sizing Calculator (Hunter's Curve / WSFU)
Size water supply pipes from fixture-unit count using Hunter's Curve and an 8 ft/s velocity limit
Planet Altitude & Azimuth Calculator
Compute a planet's position (alt/az) for any date, time, and location
Plant Watering Interval Calculator
Calculate how often to water based on plant type, pot, and climate
Poland ZUS Contribution Calculator
Calculate Polish ZUS social insurance contributions for employee and employer.
Pet Pool / Paddling Pool Chemistry Calculator
Calculate chlorine and pH adjustment doses for a small pool
Print Cooling Fan Curve Calculator
Map fan percentage to PWM duty cycle for your printer's part-cooling fan
3D Print Time Estimator
Rough print time estimate from object height, layer height, and print speed
Psychrometric Dew Point & Wet Bulb Calculator
Find dew point, wet-bulb temperature, humidity ratio, and enthalpy from dry-bulb and relative humidity
Pump Total Dynamic Head (TDH) Calculator
Calculate total dynamic head from static lift, friction, and velocity head
RC Aircraft Wing Loading Calculator
Calculate wing loading and a stall-speed estimate for RC planes
Receptacle Circuit Count Calculator
Calculate the minimum 20 A small-appliance and dedicated dwelling circuits required by NEC 210.11
Film Reciprocity Failure Calculator
Correct long-exposure times for reciprocity failure on common film stocks
Reef Calcium Dosing Calculator
Calculate daily calcium, alkalinity, and magnesium dosing for reef tanks
Refractometer FG Correction Calculator
Convert refractometer Brix readings to true final gravity after fermentation.
Refrigerant Charge (Subcooling Method) Calculator
Verify TXV-system charge from liquid-line subcooling against the manufacturer target
Refrigerant Oil Charge Calculator (Line Set Extension)
Calculate extra compressor oil needed when extending line sets beyond factory specification
Residential Optional Load Calculation (NEC 220.82)
Fast residential service sizing using the NEC 220.82 optional calculation method
Resin Exposure Time Calculator
Get starting base and normal layer exposure times for SLA/MSLA resin
Reverb Room Size to Pre-Delay Calculator
Derive natural pre-delay from simulated room size and listener position
Room Mode (Standing Wave) Calculator
Find axial, tangential, and oblique room modes for acoustic treatment.
Seed Germination Rate & Sowing Density Calculator
Calculate seeds to sow for a target plant stand given germination rate
Garden Seed Spacing & Row Calculator
Calculate how many plants fit in your garden bed by spacing
Septic Tank Sizing Calculator
Size a residential septic tank from bedroom count using standard daily-flow design tables.
Service Entrance Conductor Sizing Calculator
Size service entrance conductors from a calculated service load per NEC 230.42 and 310.12
Service Load Calculation (NEC 220)
Compute residential service load per NEC 220.82 optional dwelling-unit method
Short-Circuit Current Rating (SCCR) Calculator
Find available fault current at any point in a distribution system for SCCR and AIC verification
Shotgun Shot String & Pattern Calculator
Evaluate shotgun pattern density and pellet count at range
Singapore CPF Contribution Calculator
Calculate Singapore CPF contributions by age band, with the OA/SA/MA split.
Single-Phase Panel Load Balancing Calculator
Balance circuit loads across panel legs to minimize neutral current and optimize panel capacity.
Drain Pipe Slope / Fall Calculator
Calculate fall in inches over a run for 1/8, 1/4, or 1/2 inch per foot drain slopes
Solar DC Cable Sizing Calculator (NEC 690.8)
Size PV DC conductors per NEC 690.8 ampacity and check voltage drop on string runs.
Off-Grid Solar System Calculator
Size solar panels, batteries, and inverter for any off-grid system
Solar PV System Sizing Calculator
Estimate how many solar panels you need to cover your energy consumption.
Solar Water Heating System Sizing Calculator
Size solar collector area and storage volume for a domestic solar hot water system.
Solunar Feeding Times Calculator
Calculate major and minor solunar feeding periods for any date and location.
Spain Seguridad Social Contribution Calculator
Split Spanish Social Security between employee and employer
SRM Beer Color Calculator (Daniels)
Estimate beer color using Ray Daniels' MCU-based formula
SRM Beer Color Calculator (Morey)
Predict beer color in SRM and EBC using the Morey equation
Stamp Condition Grade Reference
Compare philatelic grade descriptions (P, F, VF, XF, Superb) for stamps
500 Rule & NPF Star Trail Calculator
Find the longest exposure before stars trail, for any focal length
Step Mash Infusion Calculator
Calculate the boiling-water volume to add for each step mash temperature rest.
Photography Stop Calculator
Find the EV stops between two aperture, shutter speed, or ISO values
Studio Monitor Placement Calculator
Find the ideal monitor distance, angle and position for your room
Subpanel Sizing Calculator
Determine subpanel ampacity, feeder wire, and breaker size from your circuit load list.
Sunny-16 Exposure Rule Calculator
Apply the Sunny-16 rule to find exposure settings in any lighting condition
Superheat Calculator (Fixed-Orifice Systems)
Find suction-line superheat from suction pressure and temperature to set the charge
Surge Protective Device (SPD) Sizing Calculator
Select SPD type, MCOV, and discharge current for service-entrance and branch use.
Knit Sweater Sizing Calculator
Calculate stitch counts and sleeve lengths for a custom-fit sweater
Sweden Social Security (Arbetsgivaravgift) Calculator
Calculate Swedish employer social contribution rates by age group
Swing & Groove Timing Calculator
Calculate note timing shifts for swing, shuffle, and groove feels
TCG Swiss Tournament Round Calculator
Calculate number of Swiss rounds needed for a TCG tournament
Simplified Tide Height Calculator
Estimate tide height between high and low water using the Rule of Twelfths.
Top/Bottom Layer Count to Thickness
Convert top and bottom solid layer counts into total thickness in mm
Trolling Depth Calculator
Estimate lure depth for lead core or braided trolling line
UK Statutory Redundancy Pay Calculator
Calculate UK statutory redundancy entitlement by age and length of service.
UK Statutory Maternity Pay Calculator
Calculate SMP weekly amounts across the 39-week statutory entitlement.
US Social Security Benefit Estimator
Estimate monthly Social Security retirement benefit from earnings
Vent Pipe Sizing Calculator (IPC 906)
Size vents from connected drainage fixture units and developed vent length per IPC Table 906.1.
Video Bitrate & Storage Calculator
Estimate video file size from bitrate, frame rate and duration
Wargame Charge Range & Reach Calculator
Find reliable charge range and reach for a 2D6 wargame unit
Warhammer 40K Army Points Calculator
Build and tally Warhammer 40K army lists within points limits
Warhammer Kill Team Points Calculator
Build Kill Team rosters and stay within your point limit
Warping Risk Assessor
Assess warping risk for a print based on material, geometry, and settings
Brewing Water Chemistry Calculator
Calculate salt additions to hit target water ion profiles
Residual Alkalinity Calculator for Brewing
Calculate residual alkalinity to predict mash pH direction
Water Treatment Equipment Flow Rate Calculator
Size water softeners, filters, and RO systems from daily demand and peak flow rate.
Watts to Amps Calculator
Convert load watts to amps given voltage and power factor for any phase configuration
Wildlife Track & Gait Spacing Reference
Identify animal gait patterns from track spacing measurements
Wind Drift Calculator for Rifle Shooting
Calculate wind deflection for any bullet at distance
Wire Ampacity Calculator (NEC 310.16)
Look up conductor ampacity from the NEC 310.16 table by AWG/kcmil and insulation type
Wort Chiller Cooling Time Estimator
Estimate how long it takes to chill wort to pitching temperature
Z-Offset First Layer Calculator
Calculate Z offset adjustment from first-layer squish measurements.
Alveolar-Arterial (A-a) Gradient Calculator
Assess pulmonary gas exchange from ABG and FiO2
Paracetamol Toxicity Nomogram (Rumack-Matthew)
Plot serum paracetamol level vs time to guide NAC treatment
ADA / Section 508 Accessibility Checklist
Interactive checklist for US federal and commercial accessibility law
Agricultural Water Quality Compliance Checker
Check setback distances and application windows for nutrient management plan compliance
EU AI Act Conformity Assessment Pathway
Map the conformity assessment route required for your high-risk AI system
AI Liability Risk Scorer (EU AI Liability Directive)
Estimate civil liability exposure under the proposed EU AI Liability Directive
AI Model Training Carbon Estimator
Estimate the CO2e of training a machine-learning model from hardware, time, and grid intensity
AI Training Data Rights Checker
Check if using a dataset for AI training is lawful under copyright and data-protection law
Air Cargo Revenue Tonne-Kilometre Calculator
Calculate RTK, ATK, and load factor for air cargo performance benchmarking
Algorithmic Bias Self-Audit Tool
Self-audit an AI decision-making system for bias risk across protected characteristics.
Aminoglycoside Extended-Interval Dosing Nomogram
Tobramycin and amikacin once-daily dosing from patient kidney function
AMM Price Impact Calculator
Calculate price impact for large trades on constant-product AMMs
Sill Plate Anchor Bolt Layout Calculator
Calculate anchor bolt count, spacing, and edge distances per IRC rules
Anchor Scope & Chain Calculator
Calculate required anchor chain scope for safe holding in any depth and conditions
Anaesthetic Gas Flow Rate Calculator
Calculate fresh gas flow and volatile agent consumption for inhalation anaesthesia
Antibiotic PK/PD Target Attainment Calculator
Predict fT>MIC, AUC/MIC, or Cmax/MIC for time- or conc-dependent antibiotics
Antibiotic MIC Breakpoint Interpreter (EUCAST/CLSI)
Classify S, I, or R from an MIC using breakpoint tables
APACHE II Score Calculator
ICU severity of illness and mortality estimation
Argentina IVA Calculator
Calculate Argentine IVA at 21% / 10.5% / 27% by category — instant in your browser.
Australia Annual Leave Entitlement Calculator
Calculate Australian 4-weeks minimum annual leave with shift-worker rules
Australia Concessional Contributions Cap Checker
Check your Australian concessional super cap and catch-up room
Australia Government Parental Leave Pay Calculator
Calculate Australian government-funded parental leave pay (DGEPP)
Australia Sole Trader Tax Calculator
Calculate Australian ABN-holder income tax, Medicare levy and LITO offset
Australia Public Holiday Counter
Count Australian working days excluding state-specific public holidays
Aviation Fuel Reserve Calculator (VFR/IFR)
Calculate trip, alternate, and 45-minute reserve fuel per FAR 91.151/91.167
Aviation Noise Exposure Reference Tool
Look up aircraft noise category, EPNdB limits, and Stage/Chapter classification
Ballast Calculation Tool
Find the ballast water mass needed to reach a target draft after discharge
Simple Beam Load & Deflection Calculator
Calculate max bending moment, shear force, and mid-span deflection for beams
Beaufort Scale Wind & Sea State Reference
Convert Beaufort force to wind speed, wave height, and sea-state description
Bee Colony Honey Yield Estimator
Estimate seasonal honey yield from colony strength, forage area, and nectar flow
Bicarbonate Deficit Calculator
Estimate total bicarbonate replacement in metabolic acidosis
Billable Hours Calculator
Convert time entries to billable fees at multiple rate tiers in seconds
Biometric Data Processing Impact Checker
Check lawfulness and safeguard requirements for biometric data under GDPR
Bishop Score for Labour Induction
Cervical readiness score to predict induction success
Solidity Gas Limit Estimator
Estimate gas for common EVM operations and Solidity patterns
Board Feet Calculator
Calculate board feet from thickness, width, and length in seconds
Boring Bar Deflection Calculator
Estimate boring bar tip deflection under cutting force for overhang ratios
Brazil Férias (Annual Leave) Calculator
Calculate Brazilian CLT vacation entitlement plus the one-third constitutional bonus.
Brazil Public Holiday Counter
Count Brazilian working days excluding national and state holidays
Brazil Rescisão Trabalhista Calculator
Estimate a CLT termination payout — saldo, férias, 13° and the FGTS fine.
Bitcoin Difficulty & Block Time Estimator
Estimate the next difficulty adjustment from the current hashrate trend
Cable Tray Fill Calculator (NEC 392)
Verify cable tray fill area for single and multiconductor cables per NEC Article 392.
Calcium–Phosphorus Product Calculator
CKD cardiovascular risk from Ca x P product in dialysis patients
Canada EI Premium Calculator
Calculate Canadian Employment Insurance premiums for employee and employer
Canada Public Holiday Counter
Count Canadian working days by province (provincial holidays vary)
Canada RRSP Contribution Room Calculator
Work out your RRSP deduction limit from earned income
Canada Self-Employed Tax Calculator
Calculate Canadian sole-proprietor federal plus provincial tax and CPP
Canada Termination Notice Calculator
Calculate statutory minimum termination notice by Canadian province and length of service.
Car Commute Carbon Calculator
Calculate annual CO2 from your daily commute by car or public transport
Carbon Inset vs Offset Decision Tool
Decide whether value-chain insetting or market offsetting fits your strategy
Carbon Offset Cost Calculator
Calculate the cost to offset your carbon footprint at multiple market tiers
Freight Carbon Footprint & Offset Calculator
Calculate CO2e emissions per tonne-km for road, rail, sea, and air freight
Carboplatin AUC Dose Calculator (Calvert Formula)
Oncology carboplatin dose from a target AUC and GFR
Cargo Insurance Premium Estimator
Estimate marine cargo insurance premium from commodity, value, and voyage
Cargo Theft & Loss Recovery Calculator
Estimate cargo claim recovery after deductibles, depreciation, and carrier liability caps
CBAM Carbon Cost Estimator
Estimate EU Carbon Border Adjustment Mechanism costs on imports
CBAM Certificate Quantity & Cost Planner
Plan CBAM certificate purchases and cost for your import declaration
CBDC vs Crypto vs Stablecoin Comparison Tool
Compare central bank digital currencies, stablecoins, and crypto on key risk dimensions
CE Marking Decision Tree
Find the right CE directives and conformity route for your product.
Cell Density from OD600 Calculator
Convert absorbance at 600 nm to cells/mL or CFU/mL
Cell Viability Calculator (Trypan Blue Exclusion)
Calculate live cell count and viability % from haemocytometer data
Cell Doubling Time Calculator
Calculate population doubling time from two cell counts
Center Drill Depth Calculator
Calculate center-drill plunge depth to create the correct 60-degree center
CHA₂DS₂-VASc Score Calculator
Stroke risk in atrial fibrillation for anticoagulation decisions
CHADS₂ Stroke Risk Score
Original stroke risk tool for AF patients
Charter Party Freight Calculator
Calculate voyage freight, laytime, and despatch or demurrage from CP terms
Child-Pugh Score Calculator
Cirrhosis severity classification A, B, or C
Child Support Estimator by State
Estimate monthly child-support obligations using income-shares or percentage models
Chile IVA Calculator
Add or extract Chile's flat 19% IVA — instant result in your browser.
China Public Holiday Counter
Count Chinese working days with Golden Week and day-swap adjustments
Chip Load Calculator
Back-calculate chip load per tooth from measured feed rate
Circular Economy Maturity Assessment
Assess your company's circular economy maturity across design, use, and recovery
Civil Damages Calculator
Tally economic, non-economic, and punitive damages for a civil claim
Climate Risk TCFD Screener
Screen physical and transition climate risks for TCFD disclosure
Cloud Base Calculator
Estimate convective cloud base from surface temperature and dew point spread
Codon to Amino Acid Translator
Translate a DNA or RNA codon sequence into its amino acid sequence
Collet Runout Tolerance Calculator
Estimate total indicator runout (TIR) at the tool tip from collet specs
Colombia IVA Calculator
Calculate Colombian IVA at 19% / 5% / 0% by product category — runs in your browser.
Combustion Air Opening Size Calculator (IMC 701)
Size combustion air openings for fuel-burning equipment rooms per IMC 701
Commercial Lease Rent Escalation Calculator
Project total rent over a lease term with fixed or CPI-style escalations
Container Lashing Force Calculator
Calculate lashing forces on deck containers using ship motion and stow geometry
Container Load Planner (20ft/40ft/TEU)
Estimate how many pallets or cartons fit into a 20ft, 40ft, or HC container
Container Stuffing & Utilisation Calculator
Maximise CBM utilisation and check weight limits for container loading
Contingency Fee Calculator
Calculate attorney fees, costs, and net-to-client on contingency cases
Contract Notice Period Calculator
Compute contractual notice expiry dates for termination or renewal clauses
Cookie Consent Compliance Checker
Check your cookie banner against GDPR, ePrivacy, and ICO guidance
Copyright Term Calculator
Determine whether a US work is still in copyright or in the public domain
CS3D / CSDDD Applicability Checker
Check if your company is in scope for the EU Corporate Sustainability Due Diligence Directive
Potassium Shift Calculator (pH Correction)
Estimate true potassium after correcting for blood pH
Corrected Sodium for Hyperglycaemia
Adjust measured serum sodium for elevated blood glucose
Countersink Depth Calculator
Find countersink depth for any screw head diameter and countersink angle
Court Deadline Calculator
Count calendar or business days to compute litigation deadlines accurately
CrCl-Based Renal Drug Dosing Interval Selector
Renal dose reduction guidance for common drugs
Crop Insurance Premium Estimator
Estimate federal crop insurance premium for APH and revenue protection plans
Crop Rotation Nitrogen Credit Calculator
Estimate nitrogen credit from a previous legume crop to cut fertilizer needs
Crosswind & Headwind Component Calculator
Resolve wind into headwind and crosswind components for any runway
Crypto Collateral Swap & Refinancing Cost Calculator
Calculate the all-in cost of swapping collateral in a DeFi lending position.
Crypto DCA Backtest Tool (Manual Data)
Backtest a dollar-cost averaging strategy with manually entered price history
Crypto DCA Target Price Calculator
Calculate how many DCA purchases reach your target average cost basis
Crypto Futures PnL Calculator
Calculate realised P&L on a closed long or short futures position
Crypto Estate & Inheritance Planning Checklist
Generate a personalised crypto asset inheritance checklist for estate planning.
Crypto Portfolio Diversification Scorer
Score your crypto portfolio's diversification across asset types and correlation
Crypto Position Size & Risk Calculator
Calculate position size from account risk, entry, and stop-loss
Crypto Tax Lot Calculator (FIFO / LIFO / HIFO)
Calculate capital gains/losses from crypto disposals using FIFO, LIFO, or HIFO
Crypto Tax Treatment by Jurisdiction
Look up crypto capital gains, income, and mining tax rules for 40 countries
Crypto Wash Sale Rule Tracker (US / UK)
Track potential wash-sale or bed-and-breakfasting patterns in your crypto trades
CSF Analysis Interpreter
Classify CSF results across bacterial, viral, fungal and TB meningitis
CSRD / ESG Reporting Checklist
Interactive CSRD double-materiality and ESRS disclosure checklist
CURB-65 Pneumonia Severity Score
Stratify community-acquired pneumonia for admit vs discharge
Customs Broker Fee Estimator
Estimate US customs brokerage fees by entry type, value, and services
EU Cyber Resilience Act (CRA) Applicability Checker
Check CRA obligations for hardware/software products with digital elements
CNC Machining Cycle Time Estimator
Estimate rough CNC cycle time from toolpath length, feed rate, and rapids
EU Data Act Applicability Checker
Determine data-sharing obligations under the EU Data Act for IoT/connected products
Data Centre PUE & Carbon Calculator
Calculate PUE efficiency and CO2 footprint for your data centre or server room
DeFi Protocol Rug Pull Risk Scorer
Score a DeFi project's rug-pull risk from on-chain and structural indicators
DeFi Yield Farming Tax Liability Estimator
Estimate income tax on DeFi yield from lending, liquidity provision, and farming
DeFi Yield Optimizer Comparison
Compare DeFi strategy yields: lending, LPing, staking, vault strategies
Denmark Grøn Check / Grønt Bidrag Calculator
Calculate the Danish green tax credit for low and middle incomes
Denmark MOMS Calculator (flat 25%)
Calculate Danish 25% MOMS inclusive and exclusive in one step.
Density Altitude Calculator
Find density altitude from pressure altitude, temperature, and dew point
Diet & Food Carbon Footprint Calculator
Estimate annual CO2e from your diet — meat, dairy, plant-based
Digital Product Passport Readiness Checker
Assess readiness for the EU Digital Product Passport under Ecodesign (ESPR)
Distance to Horizon Calculator
Find geometric, refraction-corrected, and radar horizon distance from eye height
Dividing Head Calculator
Find the hole circle and turns for 40:1 simple indexing
DKA IV Fluid Regime Calculator
Calculate DKA fluid replacement and potassium supplementation volumes
DMA Gatekeeper Test
Check if your platform meets EU Digital Markets Act gatekeeper thresholds.
DNA/RNA Quantitation by Absorbance (A260) Calculator
Convert an A260 reading to ng/uL for DNA, RNA, or oligos
Document Redaction Cost Estimator
Estimate attorney-hours and cost to redact a document set for production
Water Heater Recovery Rate Calculator
Calculate recovery time and recovery rate for storage water heaters from element kW or gas BTU/h.
DORA ICT Risk Applicability Checker
Find your ICT risk duties under the EU Digital Operational Resilience Act
Data Transfer Mechanism Selector (GDPR / UK GDPR)
Choose the right cross-border data transfer mechanism under GDPR or UK GDPR
DPIA Helper — Data Protection Impact Assessment
Determine if a DPIA is required and scaffold the assessment under GDPR
Draft Survey Calculator
Calculate cargo loaded or discharged from six-point draft readings
Drain Cleanout Spacing & Location Calculator
Verify IPC cleanout requirements by pipe size and placement for horizontal and building drains.
Drill Feed & RPM per Material Calculator
Recommend drilling RPM and feed per revolution for any material and drill size
DSA Applicability Checker
Determine your Digital Services Act tier: hosting, intermediary or VLOP.
EU Accessibility Act (EAA) Applicability Checker
Determine if your product or service must comply with the EAA
Earthwork Swell & Shrinkage Calculator
Convert bank, loose, and compacted soil volumes using swell and shrinkage
EIP-1559 Transaction Fee Calculator
Calculate Ethereum EIP-1559 effective gas price, max fee, and miner tip
Embodied Carbon Calculator (Building Materials)
Estimate CO2e from construction materials: concrete, steel, timber, insulation
Environmental Permit Requirement Checker (UK/EU)
Find out if your business activity needs an environmental permit
Economic Order Quantity (EOQ) Calculator
Find the optimal order quantity that minimises total inventory holding and ordering cost
Extended Producer Responsibility Fee Estimator
Estimate EPR packaging fees across UK and EU markets by material and tonnage.
ePrivacy Regulation Readiness Checker
Assess your cookie and tracking setup against the forthcoming EU ePrivacy Regulation
EU AI Act Risk Classifier
Classify your AI system's risk tier under the EU AI Act
EU Carbon Removal Certification (CRCF) Eligibility Checker
Check if your carbon removal activity qualifies under the EU CRCF framework
EU Ecolabel Eligibility Checker
Check if your product or service category is eligible for the EU Ecolabel
SFDR Product Classification Checker
Classify a fund as Article 6, 8, or 9 under the EU SFDR
EU Taxonomy Eligibility & Alignment Checker
Check if your economic activity qualifies as environmentally sustainable under EU Taxonomy
EU Public Holiday Counter
Count working days between dates for any EU27 country
EU Deforestation Regulation (EUDR) Checker
Check if your commodities fall under the EU deforestation due-diligence rules
EV Range & Efficiency Calculator
Estimate electric vehicle range from battery capacity, efficiency, and conditions
EV vs Petrol Lifetime CO2 & Cost Comparator
Compare lifetime emissions and cost: electric vs petrol or diesel car
Eviction Timeline Estimator
Map out required notice, filing, hearing, and lockout dates by US state
Hydronic Expansion Tank Sizing Calculator
Size a closed hydronic expansion tank from system volume, pressure, and temperature range.
Morse Fall Risk Scale Calculator
Six-item inpatient fall risk assessment tool
Fascia, Soffit & Eave Material Calculator
Estimate fascia board, soffit panel area, and J-channel for any roof perimeter
F-Gas Quota & HFC Phase-Down Calculator
Calculate F-gas CO2-equivalent and check EU quota phase-down position
Fillet Weld Size & Strength Calculator
Calculate the required fillet weld leg size to carry a given shear or tensile load
Fillet Weld Effective Throat Calculator
Calculate effective and theoretical throat size from leg size for any weld profile
Flight Carbon Footprint Calculator
Calculate CO2e emissions for any flight with radiative forcing
Flight Plan Fuel Summary Calculator
Summarize multi-leg fuel burn, reserves, and total required fuel for a flight plan
Floor Joist Span Calculator
Verify allowable floor joist span for lumber size, species, and live load
24-Hour Fluid Balance Calculator
Tally ins and outs for daily net fluid balance on the ward.
Footing Size Calculator
Calculate minimum footing area and depth from column load and soil bearing capacity
France Auto-Entrepreneur Charges Calculator
Calculate French micro-entrepreneur cotisations sociales and IR prélèvement libératoire
France CESU Déclaré Tax Credit Calculator
Calculate the French 50% tax credit for declared home-service workers
France Congé Paternité Calculator
Calculate French paternity/co-parent leave days and IJSS indemnity
France Congés Payés Calculator
Calculate French paid leave entitlement (5 weeks) and acquisition month
France PER (Plan d'Épargne Retraite) Deduction Ceiling Calculator
Calculate your French PER maximum deductible contribution (plafond)
Franchise Royalty & Fee Calculator
Calculate monthly franchise royalties, ad-fund contributions, and net-to-franchisee
Freight Class (NMFC) Calculator
Determine LTL freight class from density, stowability, handling, and liability
Aircraft Fuel Burn & Endurance Calculator
Calculate endurance, range, and reserve fuel from burn rate and usable fuel
Fuel Cost vs CO2 Comparator
Compare petrol, diesel, LPG, and EV on cost and CO2 per mile
Fuel Oil Storage Tank Sizing Calculator
Size a No. 2 fuel oil storage tank from boiler BTU/h and heating degree days.
Freight Fuel Surcharge Calculator
Calculate carrier fuel surcharges from base rate and published FSC percentage
Crypto Funding Rate Cost Calculator
Calculate the annualised cost of holding a perpetual futures position
Boiler Replacement Sizing Calculator
Size a replacement hot-water boiler from Manual J heat loss or connected radiation.
Gas Appliance Combustion Efficiency Calculator
Estimate stack efficiency from flue gas O₂ or CO₂ and temperature (Siegert)
Natural Gas / Propane Pipe Sizing Calculator
Size black iron or CSST gas supply piping from total BTU/h demand per NFPA 54 longest-length method.
Gas Safety Compliance Checker (UK Landlord)
Check UK landlord gas safety duties under the Gas Safety Regulations 1998
GC Content Calculator
Calculate GC percentage and base composition for any nucleotide sequence
Trade Intensity & Export Revenue Estimator
Estimate export revenue potential by market using GDP per capita and trade intensity
GDPR Fine Estimator
Estimate potential GDPR penalty range using Article 83 tier and annual revenue
Gentamicin Once-Daily Dosing Calculator
Hartmann nomogram-based extended-interval aminoglycoside dosing
Germany Annual Leave Entitlement Calculator
Calculate German Mindesturlaub and contractual vacation days
Germany Elterngeld Calculator
Calculate German parental benefit (Basiselterngeld / ElterngeldPlus)
Germany Freiberufler Tax Calculator
Calculate German self-employed income tax, Soli and church tax on your Gewinn
Germany Haushaltsnahe Dienstleistungen Tax Credit Calculator
Calculate the German §35a household-services tax credit (20% of labour cost)
Germany Kurzarbeitergeld Calculator
Calculate German short-time work (KUG) benefit amount
Germany Riester Rente Contribution Calculator
Calculate minimum Riester contribution for full state allowance (Zulage)
Glasgow Coma Scale (GCS) Calculator
Score eye, verbal, and motor responses for consciousness level
Glide Distance Calculator
Calculate engine-out glide range and time aloft from height and glide ratio
Global Plastics Treaty Readiness Checker
Assess your plastic product strategy against the proposed UN Plastics Treaty
GRACE ACS Outcome Score
In-hospital and 6-month mortality risk in ACS
Grain Shrink & Drying Cost Calculator
Calculate shrink weight loss and drying cost to reach standard moisture
Grease Trap / Interceptor Sizing Calculator
Size a hydromechanical grease interceptor by fixture-unit flow rate per IAPMO Z1001.
Green Lease Clause Scorer
Score a commercial lease against green lease best-practice clauses
Greenwashing Risk Scorer
Score your sustainability claims for greenwashing risk under the EU Green Claims Directive
Greywater Reuse System Sizing Calculator
Estimate daily greywater supply and size a storage tank for toilet flushing or irrigation reuse.
IGF-1 Standard Deviation Score Calculator
Compute IGF-1 SDS from age- and sex-specific reference ranges
GZ Stability Curve Basic Estimator
Estimate righting lever GZ values and metacentric height from simplified ship inputs
Hardness Conversion Calculator
Convert between Rockwell C (HRC), Brinell (HB), Vickers (HV), and tensile strength
Harvest Moisture Loss & Shrink Calculator
Calculate actual vs. standard-moisture bushels and moisture-shrink cost at harvest
Smart Contract Security Audit Checklist
Self-audit a Solidity contract against common vulnerability classes
Hazmat / Dangerous Goods Surcharge Estimator
Estimate hazmat surcharges for ground, air, and ocean dangerous goods
HEART Score for Chest Pain
Identify low-risk chest pain for safe ED discharge
Heat Pump COP & HSPF Calculator
Calculate heat pump COP from output and power, and estimate seasonal HSPF
Haematologic Response Criteria Calculator (CR/VGPR/PR)
Classify myeloma treatment response by IMWG criteria
Herbicide / Pesticide Tank Mix Calculator
Calculate product volume per tank and per acre from label rate and field size
HIPAA Compliance Checklist
Interactive HIPAA Security Rule and Privacy Rule gap assessment
Holliday-Segar Fluid Maintenance Calculator
Maintenance IV fluid rate for paediatric and adult patients
Hong Kong MPF Contribution Calculator
Calculate Mandatory Provident Fund contributions, 5 percent each, capped
HS Code & Duty Helper
Look up HS-code chapter/heading and indicative duty rates by commodity
Human Rights Due Diligence Checker (UNGPs)
Self-assess supply-chain human rights due diligence against the UNGPs
Whole-House Dehumidifier Sizing Calculator
Size a whole-house dehumidifier from latent moisture load and infiltration
Ductwork Heat Gain / Loss Calculator
Estimate BTU/h heat gain or loss from supply and return ducts in unconditioned spaces.
Heat Exchanger NTU-Effectiveness Calculator
Find heat exchanger effectiveness and outlet temperatures with the ε-NTU method.
HVAC Cooling & Heating Load Estimator (Manual J Simplified)
Estimate BTU/h heating and cooling loads from room area and envelope
Refrigerant GWP & EPA Section 608 Quantity Calculator
Calculate annual leak rate and the EPA-required repair trigger from system charge weight.
HVAC Zoning System Load & Bypass Calculator
Size a bypass damper for a zoned forced-air system and verify minimum zone flow
Hydronic Circulater Pump Selection Calculator
Get system GPM and head loss to select a residential hydronic zone circulator
IATA Live Animal Regulations Quick Reference
Look up container type, ventilation, and document requirements for air live-animal shipments
Industrial IoT Cybersecurity Risk Checker (IEC 62443)
Assess ICS and OT system cyber risk against IEC 62443 security levels
Impermanent Loss Calculator
Calculate impermanent loss for AMM liquidity pool positions
Incoterms 2020 Selector & Reference
Choose the right Incoterm and see risk-transfer, cost, and clearance rules
India Earned Leave Calculator
Calculate Indian statutory earned leave under the Factories Act or a state Shops Act.
India Gratuity Calculator
Calculate Payment of Gratuity Act entitlement with the 15/26 formula and ₹20 lakh cap.
Indonesia PPN Calculator
Add or extract Indonesia's 11% PPN — instant result in your browser.
INR Reversal — FFP or PCC Dose Calculator
Calculate FFP units or PCC dose to reverse an elevated INR
Insulin Sliding Scale & Drip Rate Calculator
Build a correction scale and convert insulin units/hr to a pump rate
Internal Carbon Price (ICP) Impact Calculator
Model the P&L impact of an internal carbon price across business units
International Freight Cost Estimator
Estimate door-to-door import cost including freight, duty, VAT, and fees
Ionised Calcium Estimator from Total Calcium and pH
Estimate ionised Ca when direct measurement is unavailable
Ireland Universal Social Charge (USC) Calculator
Calculate Irish USC across the four income bands
ISO Tolerance & Fit Calculator
Find hole and shaft limits for any ISO fit class and nominal diameter
ISO 14001:2015 Environmental Management Gap Checker
Self-assess ISO 14001 EMS readiness before certification
ISO 27001:2022 Gap Checker
Identify ISO 27001 Annex A control gaps before certification
Israel Bituach Leumi Contribution Calculator
Calculate Israeli national insurance and health tax at reduced and full rates.
IV Solution Tonicity & Compatibility Estimator
Check tonicity of compounded IV admixtures before infusion
IV Drip Rate Calculator
Compute drops/min or mL/hr for any IV infusion setup
Japan Childcare Leave (育児休業) Benefit Calculator
Calculate Japanese 育児休業給付金 (childcare leave benefit) during parental leave
Japan Working Day Counter
Count Japanese working days excluding 国民の祝日 and substitute holidays
Jury Duty Pay Calculator
Calculate total jury pay, employer supplement, and income gap for any US state
Kleihauer-Betke Feto-Maternal Haemorrhage Estimator
Estimate feto-maternal bleed volume and anti-D dose
Knurling RPM & Feed Calculator
Calculate spindle speed and feed for clean straight or diamond knurling
Lactate Clearance Calculator
Percentage lactate clearance as a sepsis resuscitation endpoint
Landed Cost Calculator
Calculate total landed cost per unit including CIF, duty, tax, and fees
Lathe Taper Calculator
Calculate compound-slide angle or tailstock offset for any taper
Simplified LCA Hotspot Identifier
Identify the top carbon and energy hotspots across a product's lifecycle
Lease Break Penalty Calculator
Calculate lease-termination penalties, re-letting fees, and landlord duty to mitigate
Lighting Power Density (LPD) Calculator
Calculate installed lighting power density in W/ft² and compare against ASHRAE 90.1 limits.
Liquidity Pool Position Value Calculator
Track current value and fee income of a Uniswap V2 LP position
LLC Dissolution Asset Distribution Calculator
Compute member distributions after paying LLC debts and liquidation costs
LPG / Propane Conversion & Sizing Calculator
Convert propane BTU to gallons, size a storage tank, and check orifice sizing vs natural gas.
LTL vs. FTL Decision Tool
Compare cost-per-cwt for LTL and FTL to find the break-even shipment size
Mach Number Calculator
Convert between true airspeed and Mach number at any air temperature
Manure Application Rate Calculator
Calculate manure nutrient loading and required application rate for crop nutrient needs
Crypto Licence Jurisdiction Checker
See which jurisdictions require a licence for your crypto-asset service
Masonry Lintel Load Calculator
Find the load on a CMU or brick lintel over an opening using 45-degree arching
Maximum Allowable Blood Loss (MABL) Calculator
Perioperative transfusion trigger from blood volume and target Hb
Mediation Settlement Range Tool
Calculate a realistic settlement range using expected value and BATNA analysis
10× Medication Error Detection — Dose Plausibility Checker
Flag 10-fold dosing errors by checking calculated dose against safe range
MELD & MELD-Na Score Calculator
Liver disease severity and transplant waitlist priority score
Winter's Formula — Expected pCO2 in Metabolic Acidosis
Detect superimposed respiratory disorders in metabolic acidosis
METAR Decoder
Parse and translate a raw METAR weather report into plain English
Mexico Liquidación Laboral Calculator
Calculate Mexican LFT severance: 3 months + 20 days/year + seniority premium
Mexico Public Holiday Counter
Count Mexican working days excluding mandatory Días de Descanso Obligatorio
MiCA Crypto-Asset Classification Tool
Classify your token under the EU Markets in Crypto-Assets Regulation
Microgrid Load Shedding Priority Calculator
Assign load-shedding priority tiers to circuits and find generator or battery runtime per tier.
MiFID II Retail Investor Suitability Self-Assessment
Self-assess your risk profile against MiFID II suitability criteria
MIG Wire Diameter Selector
Pick the right wire diameter for any MIG welding application and material thickness
Modern Slavery Statement Builder
Build a UK Modern Slavery Act compliant statement in minutes
Mortise & Tenon Sizing Calculator
Calculate tenon thickness, length, and cheek-glue area for structural joints
Nature-Positive Risk Screener (TNFD)
Screen business activities for nature-related dependencies and impacts (TNFD LEAP)
NEC Tap Rule Calculator (210% and 100 A Rules)
Check NEC 240.21 tap rules for 10-ft, 25-ft, and outside feeder taps
Multifamily Dwelling Load Calculation (NEC 220.84)
Size service for apartment buildings using NEC 220.84 optional demand factors
NEC Article 430 Motor Circuit Summary Calculator
Get FLC, conductor, max OCPD, overload, and disconnect for a motor in one step.
NEC Kitchen Circuit Requirements Calculator
List the dedicated kitchen circuits required per NEC 210.52, 210.8, and 210.12
Panel Schedule / Load Center Calculator
Build a load center panel schedule, auto-assign circuits to legs, and compute total demand.
NEC Chapter 9 Table 9 AC Resistance & Reactance Lookup
Look up AC resistance and reactance per 1000 ft by conductor and conduit type
Neonatal Drug Dose Reference Calculator
Weight-based neonatal dosing for antibiotics, caffeine, and NICU drugs
Net Zero Target Pathway Calculator
Build a linear or science-based net zero reduction pathway from base year
New Zealand KiwiSaver Calculator
Calculate NZ KiwiSaver contributions at 3, 4, 6, 8 or 10 percent
NEWS2 Score Calculator
National Early Warning Score 2 for patient deterioration detection
NFT Royalty Calculator
Calculate NFT royalty income across primary and secondary sales
NHTSA Complaints Lookup
Search NHTSA consumer complaints for any vehicle year, make, and model
NHTSA Vehicle Make & Model Lookup
Browse all makes and models in the NHTSA vPIC database without an API key
NHTSA Recall Lookup
Check any vehicle for open NHTSA safety recalls by VIN using the free public API
NHTSA Safety Ratings Lookup
Retrieve 5-Star Safety Ratings for any model year vehicle from NHTSA
Product Liability Classification Checker for Digital Products (EU/UK)
Find out if your digital or connected product carries producer liability
NIS2 Directive Applicability Checker
Determine if your organisation is an essential or important entity under NIS2
Nitrogen Use Efficiency (NUE) Calculator
Calculate NUE percentage from crop uptake and fertilizer applied to optimise N applications
Non-Compete Clause Reasonableness Tool
Assess non-compete enforceability by state using duration, geography, and scope
Ocean Freight Rate Comparison Tool
Compare FCL and LCL all-in costs to find the break-even CBM for your shipment
OECD Pillar Two Global Minimum Tax Calculator
Estimate top-up tax under the OECD Pillar Two 15% global minimum tax.
Crypto Options Greeks Calculator (Black-Scholes)
Calculate delta, gamma, theta, vega, and rho for crypto vanilla options
Arterial Oxygen Content (CaO2) Calculator
Calculate total oxygen content from haemoglobin and SpO2/PaO2
Oxygen Delivery (DO₂) & Consumption (VO₂) Calculator
Haemodynamic oxygen transport indices from cardiac output and Hb.
Packaging Carbon Footprint Calculator
Estimate CO2e for packaging across plastic, glass, paper, and metal
Packaging Recyclability On-Pack Labelling Checker
Check the correct recyclability label for your packaging material
Paddock Rotation Calculator
Calculate rest period, paddock number, and grazing days for rotational grazing
Paediatric Emergency Drug Dose Reference
One-weight-entry lookup for all peds ACLS and RSI drugs.
Paediatric GCS Calculator (Children <2 years)
Age-adapted Glasgow Coma Scale for infants and toddlers
Paediatric Normal Vital Signs Reference
Age-band heart rate, respiratory rate, and BP reference ranges
Pallet Load / Stack Calculator
Calculate cartons per pallet, layers, pallet weight, and stack height for shipping
Parkland Burn Formula — IV Fluid Resuscitation
Calculate 24-hour fluid resuscitation volume for burn injuries
Modified Brooke Formula — Burn Fluid Resuscitation
Alternative lower-volume 24-hour IV fluid calculation for burn injuries
Patent Term Adjustment (PTA) Calculator
Estimate USPTO PTA days under 35 U.S.C. 154(b) A, B, and C delays
PCI DSS Scope Reduction Tool
Determine your PCI DSS SAQ type and cardholder data environment scope
PCR Master Mix Calculator
Scale reagent volumes for any number of PCR reactions
Neonatal PDA Treatment Candidacy Estimator
Score clinical and echo features for PDA intervention decisions
Peru IGV Calculator
Calculate Peru's 18% IGV (16% IGV + 2% IPM) — add or extract in your browser.
Pest Economic Threshold Reference Tool
Look up economic thresholds for common field-crop pests to decide spray or no-spray
Paediatric Early Warning Score (PEWS)
Standardised early deterioration detection in children
PEX vs Copper Flow Rate Comparison Calculator
Compare pressure drop and flow rate between PEX-A, PEX-B, and Type L copper of the same size.
Phenytoin Dose Adjustment for Hypoalbuminaemia
Correct a phenytoin level for low albumin or renal failure.
PV String Sizing Calculator (Panels per String)
Find the min and max solar panels per string for an inverter MPPT window
Pipe Bevel & Saddle Layout Calculator
Generate the wrap-around cut template for pipe saddle and branch joints
Plant Population & Row-Spacing Tool
Calculate plant population per acre from row spacing and in-row seed spacing
Plasmid Insert Size Estimator
Predict gel band sizes from a restriction digest of a recombinant plasmid
Plastic Packaging Tax Calculator
Estimate UK Plastic Packaging Tax liability from weight and recycled content.
Plastic Recyclability & SUP Directive Checker
Check your plastic packaging against the EU Single-Use Plastics Directive
Platelet Transfusion Dose Calculator
Calculate platelet concentrate units needed to reach a target count
PFA-100 Closure Time Result Interpreter
Classify platelet function from PFA-100 collagen-epinephrine and ADP closure times
Plumbing Material Takeoff Calculator
Estimate supply and DWV footage, fittings, and WSFU from fixture counts for bidding.
Pipe Offset / Travel Calculator (Plumbing Isometric)
Calculate pipe cut lengths and travel for 45°, 22.5° and 60° offsets
Plumbing Rough-In Dimensions Reference
Look up standard rough-in heights and offsets for toilets, sinks, tubs, showers, and water heaters.
Water Service Meter Sizing Calculator
Size a domestic water meter from peak-demand WSFU using AWWA M22 guidelines
Plywood Sheet Optimizer
Lay out cut parts on the minimum number of sheets to cut cost and waste
Port Congestion Surcharge Reference
Look up indicative peak-season and port-congestion surcharges by trade lane
Post Base Anchor Sizing Calculator
Select post base size and concrete anchor pattern for uplift and shear loads
Power of Attorney Validity & Expiry Tracker
Track POA effective dates, renewal deadlines, and state-specific durability rules
Total Harmonic Distortion (THD) Calculator
Calculate voltage or current THD from individual harmonic magnitudes
Product Carbon Footprint Estimator
Estimate cradle-to-gate CO2e for a manufactured product
Product Ecodesign Scorecard
Score your product against EU ESPR ecodesign criteria
Pneumonia Severity Index (PSI/PORT) Calculator
Detailed 20-variable pneumonia mortality risk stratifier
QuantiFERON-TB Gold Interpretation Calculator
Apply QIAGEN cutoffs to classify a QFT IGRA result
qPCR Efficiency Calculator from Standard Curve
Calculate PCR efficiency and R-squared from a Ct vs log(template) curve
qSOFA Score Calculator
Quick bedside sepsis screening in three parameters
RBC Transfusion Expected Hb Rise Calculator
Predict post-transfusion haemoglobin from units transfused
REACH / RoHS Substance Checker
Check if your product is restricted under REACH or RoHS substance rules.
Real Estate Cap Rate & NOI Calculator
Calculate NOI, cap rate, and implied value for investment property analysis
Rebar Spacing & Lap Splice Calculator
Find bar spacing and required lap-splice length per ACI 318
Recycling Rate Estimator
Estimate your household or business recycling rate and CO2 savings
ReFi Tokenised Carbon Credit Equivalence Calculator
Compare traditional vs tokenised carbon credit pricing, verification, and retirement
Reefer / Refrigerated Cargo Cost Estimator
Estimate reefer premium and pre-trip inspection fees for perishable cargo
Reorder Point Calculator
Find the on-hand level that should trigger a replenishment order
Residential Mechanical Ventilation Calculator (ASHRAE 62.2)
Calculate whole-house ventilation CFM per ASHRAE 62.2 and IECC 2021
Retaining Wall Block Count Calculator
Estimate blocks, deadman count, and drainage stone for any retaining wall
Reticulocyte Production Index (RPI) Calculator
Determine if anaemia is hypoproliferative or hyperproliferative
Revised Trauma Score (RTS) Calculator
Physiologic trauma severity for triage and survival prediction
Right-to-Repair Product Scorer
Score your product's repairability against EU and UK rules
RPM / SFM Calculator
Convert between spindle RPM and surface feet per minute for any cutter diameter
RSI Drug Dosing Calculator
Rapid sequence intubation pre-medication, induction and paralytic doses.
Safety Stock Calculator
Set buffer inventory from demand variability, lead time, and service level
SCC Transfer Impact Assessment Tool
Assess third-country transfer risk for GDPR Standard Contractual Clauses
Scope 1 / 2 / 3 GHG Emissions Estimator
Estimate your company's GHG inventory across all three scopes
Scope 2 Market-Based vs Location-Based Emissions Comparator
Compare Scope 2 emissions under the market-based and location-based methods
Seed Cost Per Acre Calculator
Calculate seed cost per acre and per bushel of yield from bag price and seeding rate
Shear Pin Design Calculator
Calculate shear pin diameter to fail at a target torque overload
Wood Shear Wall Capacity Calculator
Look up tabulated unit shear for wood-frame shear walls per AWC SDPWS
Sheet Metal Bend Allowance Calculator
Calculate flat-pattern blank size from bend angle, radius, K-factor, and thickness
Shielding Gas Flow Rate Calculator
Determine the correct gas flow in CFH or L/min for MIG and TIG welding
Ship Fuel Consumption Calculator
Estimate voyage fuel burn and bunker cost across different speeds using the cube law
Ship Port Call Cost Estimator
Estimate port dues, pilotage, towage, and agency fees for a vessel port call
Ship Trim & List Calculator
Calculate trim and list change from loading, discharging, or shifting a weight
Ship Squat Calculator
Estimate ship squat in shallow water using the Barrass method
Shock Index Calculator
HR/SBP ratio for early haemodynamic instability detection
Singapore SRS Contribution Calculator
Calculate your SRS contribution cap and the income-tax saving it gives.
Slope & Grade Calculator
Convert between percent grade, degrees, rise/run, and ratio for any slope
Small Claims Court Limit Reference
Look up monetary jurisdictional limits for small claims court in every US state
Smart Contract Upgradeability Risk Checker
Score the centralisation risk of an upgradeable smart contract pattern
SOC 2 Readiness Checker
Self-assess SOC 2 trust service criteria gaps before your audit
Hyponatraemia Correction Rate Calculator
Safe sodium correction speed to avoid osmotic demyelination.
Sodium Deficit Calculator for Hyponatraemia Replacement
Volume of hypertonic saline needed to correct serum sodium
SOFA Score Calculator (Sequential Organ Failure Assessment)
Multi-organ failure scoring for ICU mortality estimation
Solar Panel Payback Calculator
Calculate solar PV break-even, savings, and CO2 offset over 25 years
Solar PV String Fuse Sizing Calculator (NEC 690.9)
Size string combiners and source-circuit fuses per NEC 690.9 for multi-string PV arrays.
South Africa Severance Pay Calculator
Calculate BCEA statutory retrenchment severance — one week's pay per year of service.
South Korea 4대보험 Calculator
Calculate Korean health, pension, employment and long-term-care premiums
Spain Autónomo Quota & IRPF Calculator
Calculate the Spanish self-employed Seguridad Social quota and IRPF retention
Spousal Support / Alimony Calculator
Estimate alimony duration and amount using common statutory factor models
Sputum Gram Stain Quality Checker (Murray-Washington Criteria)
Decide whether a sputum sample is acceptable for culture
Standby Power Waste Calculator
Calculate annual cost and CO2 from devices left on standby
Statute of Limitations by US State
Look up civil SOL periods for contract, injury, fraud and property claims
Structural Bolt Pretension Torque Calculator
Convert required pretension to installation torque for A325, A490, and metric bolts
Wood Stud Wall Load Calculator
Check if a stud wall carries a given axial load per NDS column provisions
Supply Chain Scope 3 Category 1 Estimator
Estimate purchased-goods emissions using spend-based or average-data methods
Theoretical Surface Finish (Ra) Calculator
Estimate theoretical surface roughness Ra from feed and nose radius
Sweden MOMS Calculator — 25% / 12% / 6%
Calculate Swedish MOMS at 25%, 12% or 6% by product category, both ways.
TAF Decoder
Translate a Terminal Aerodrome Forecast into readable plain-English periods
Taiwan Labor Insurance Calculator
Calculate Taiwanese 勞保, 健保 and 勞退 premiums by salary grade
Tank-Mix Partner Compatibility Reference
Check common herbicide and fungicide tank-mix compatibility from a static reference
Tap Drill Size Calculator
Find the correct tap-drill diameter for any UNC, UNF, or metric thread
Lathe Thread-Cutting Gear Train Calculator
Find change-gear combinations to cut any thread TPI on a non-quick-change lathe
Thread Pitch Calculator
Convert TPI to pitch and back for inch and metric threads
3:1 Descent Gradient Calculator
Calculate top of descent point and vertical speed for a 3-degree path
Tidal Height Harmonic Estimator
Estimate tidal height through the day from M2, S2, K1, and O1 constituents
Time of Useful Consciousness (Hypoxia) Reference
Look up TUC at altitude and the oxygen rules after a pressurisation failure
TIMI Risk Score for UA/NSTEMI
Seven-item risk predictor for MACE in unstable angina
Token Vesting & Cliff Schedule Visualiser
Visualise token unlock schedule with cliff, linear, and custom vesting
Tooling Cost per Part Calculator
Amortize insert or end-mill cost over expected part count, with break-even
Top of Descent (TOD) Calculator
Calculate top of descent distance for any angle, speed, and altitude change
Towing Capacity Checker
Verify whether your vehicle and trailer combo is within safe GVWR and towing limits
TPC & MCTC Calculator
Calculate Tonnes Per Centimetre and Moment to Change Trim One Centimetre
Trademark Nice Classification Lookup
Find the right Nice class and example identifications for trademark filings
Bacterial Transformation Efficiency Calculator
Calculate CFU/ug DNA from colony count and plating volume
Freight Transit Time Estimator
Estimate domestic LTL/FTL transit days by lane using standard distance bands
Transtubular Potassium Gradient (TTKG) Calculator
Assess renal potassium handling in hypo- and hyperkalaemia
Tree Equivalent Carbon Calculator
Convert your CO2e into the number of trees needed to absorb it
High-Sensitivity Troponin Serial Rise Calculator
Detect significant troponin rise for 0h/1h/3h ACS rule-in/rule-out
Trucking Cost Per Mile Calculator
Calculate fully-loaded cost per mile for owner-operators and fleets
Tumour Lysis Syndrome Risk Calculator (Cairo-Bishop)
Classify TLS risk before starting chemotherapy
Turkey SGK Contribution Calculator
Calculate Turkish social security (SGK) employee and employer shares.
UK Annual Leave Entitlement Calculator
Calculate UK statutory holiday entitlement (5.6 weeks) for full and part-time
UK CIS Deduction Calculator
Calculate UK Construction Industry Scheme tax deduction rates
UK ISA Annual Allowance Calculator
Calculate remaining ISA allowance and split across Cash/Stocks/LISA/JISA
UK Statutory Notice Period Calculator
Calculate minimum UK notice under the Employment Rights Act 1996 for either side.
UK SDLT Stamp Duty Land Tax Calculator
Calculate UK Stamp Duty Land Tax on residential and commercial property purchases.
UK Self-Employed Tax & NI Calculator
Calculate UK sole-trader income tax, Class 2 and Class 4 NI from your profit
UK Shared Parental Leave Calculator
Calculate SPL weeks and pay split between partners
UK Universal Credit Earnings Taper Calculator
Calculate UC entitlement after the 55p earnings taper
Under-Keel Clearance Calculator
Compute available UKC accounting for draft, squat, tide, and water density
Urinalysis Result Interpreter
Translate dipstick and microscopy findings into clinical differentials
US Backup Withholding Calculator
Calculate 24% IRS backup withholding on non-employee compensation.
California Meal & Rest Break Compliance Calculator
Calculate CA Labor Code meal/rest break obligations and premium pay
California Daily Overtime Calculator
Calculate CA daily overtime (1.5× after 8h, 2× after 12h)
US FMLA Leave Eligibility Calculator
Check FMLA eligibility and the 12-week / 480-hour entitlement from a hire date.
US HSA Contribution Limit Calculator
Compute your 2025 HSA limit for self-only or family HDHP coverage
US Federal FLSA Overtime Calculator
Calculate US federal overtime (1.5× after 40 hours per week)
US Self-Employment Tax Calculator
Estimate US Schedule SE tax (the 15.3% Social Security + Medicare share)
US W-4 Federal Withholding Estimator
Estimate federal tax withholding and the W-4 Step 4(c) adjustment
Vancomycin Dosing & AUC/MIC Calculator
Estimate vancomycin dose and interval from renal function
VAV Box Sizing Calculator
Size VAV terminal boxes by peak cooling CFM, minimum heating flow, and reheat capacity
Vehicle Accident Economic Damages Calculator
Total vehicle repair, rental, wage loss, and medical specials for an auto claim
VFD Motor Cable Derating & Shielded Cable Calculator
Conductor derating and shielded cable specs for variable-frequency drive installs
VIN Model Year Decoder
Instantly decode the model year from VIN position 10 for any year 1980–2040
VIN Structure Decoder
Break any VIN into its WMI, VDS, and VIS sections with field-level explanations
Visa Bulletin Wait-Time Estimator
Estimate years to a green card from historical priority-date movement
Warehouse Pick Rate Calculator
Calculate lines per hour, picks per shift, and labour cost per order line
Warehouse Slotting Velocity Tool
Assign pick-face slots by ABC velocity and ergonomic zone to reduce travel
Warfarin Dose Estimator (Gage Algorithm)
Estimate an initial warfarin dose from clinical and genetic factors.
Warfarin INR Dose Adjustment Calculator
Calculate a weekly warfarin dose change from the current INR
UK Waste Duty of Care Compliance Checker
Check your legal duties when producing, transporting, or disposing of business waste
Waste Hierarchy Optimizer
Find the highest waste hierarchy option for your material under the EU WFD
Water Footprint Calculator
Estimate your personal or product water footprint in litres
Water Heater Sizing Calculator
Size a storage or tankless water heater from peak-hour demand and incoming water temperature.
WEEE Compliance Checker
Check WEEE obligations for electrical and electronic equipment producers.
Weld Symbol Decoder
Decode AWS A2.4 weld symbols into plain-English joint instructions
Welder Duty Cycle Calculator
Check whether your welder can sustain a job's required on-time percentage
Welding Distortion Estimator
Estimate angular and longitudinal distortion for common weld joints
Welding Heat Input Calculator
Calculate arc energy input in kJ/mm or kJ/in for procedure qualification
Wells DVT Score with D-Dimer Interpretation
Combine the Wells score with D-dimer to drive the DVT pathway
Wells Score for DVT
Pre-test probability for deep vein thrombosis
Wells Score for Pulmonary Embolism
Clinical pre-test probability for PE to guide CTPA decisions
Whistleblowing Policy Builder
Generate a whistleblowing policy under the EU Whistleblower Directive and UK PIDA.
Window Rough Opening Calculator
Convert window or door unit size to the framed rough opening dimensions
WMI Country & Manufacturer Lookup
Find the country of manufacture and brand from a VIN's first three characters
Wood Framing Member Count Calculator
Calculate studs, plates, headers, and blocking for walls and openings
Worker Wellbeing & Social Baseline (S-KPI) Calculator
Calculate social KPIs for CSRD S1 worker wellbeing disclosure
Workers' Compensation Benefit Estimator
Estimate temporary and permanent disability benefits from average weekly wage
Wrongful Termination Back Pay Calculator
Estimate back pay, front pay, and benefits loss in wrongful-discharge claims
Albuquerque Commute Cost Calculator
Compare your true monthly commuting cost in Albuquerque — transit vs. driving
Albuquerque Cost-of-Living Index
Compare Albuquerque living costs (index near 90) to the US national average.
Albuquerque Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Albuquerque
Atlanta Commute Cost Calculator
Calculate your true monthly commuting cost in Atlanta — transit vs. driving.
Atlanta Cost-of-Living Index
Compare Atlanta living costs (index: 107) to the US national average.
Atlanta Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Atlanta neighborhoods.
Austin Commute Cost Calculator
Calculate your true monthly commuting cost in Austin — transit vs. driving.
Austin Cost-of-Living Index
Compare Austin living costs (index 120) to the US national average.
Austin Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Austin
Baltimore Commute Cost Calculator
Calculate your true monthly commuting cost in Baltimore — transit vs. driving.
Baltimore Cost-of-Living Index
Compare Baltimore living costs (index: 103) to the US national average.
Baltimore Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Baltimore neighborhoods
Big Integer Calculator
Perform arithmetic on arbitrarily large integers beyond float64
Boston Commute Cost Calculator
Compare your true monthly Boston commute cost — transit vs. driving
Boston Cost-of-Living Index
Compare Boston living costs (index 162) to the US national average
Boston Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Boston
Chicago Commute Cost Calculator
Compare your true monthly commute cost in Chicago — transit vs. driving
Chicago Cost-of-Living Index
Compare Chicago living costs against the US national average by category
Chicago Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Chicago neighborhoods.
Dallas Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Dallas neighborhoods.
Denver Commute Cost Calculator
Compare driving vs RTD transit for your true monthly Denver commute cost
Denver Cost-of-Living Index
Compare Denver living costs (index: 121) to the US national average.
Denver Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Denver districts
Houston Commute Cost Calculator
Calculate your true monthly commuting cost in Houston — transit vs. driving
Houston Cost-of-Living Index
Compare Houston living costs (index 96) to the US national average.
Houston Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Houston neighborhoods
Las Vegas Commute Cost Calculator — RTC Transit vs. Driving
Compare your true monthly Las Vegas commuting cost: RTC transit pass vs. driving with gas, parking, and depreciation.
Las Vegas Cost-of-Living Index
Compare Las Vegas living costs (index: 99) to the US national average
Las Vegas Parking Cost Estimator — Daily, Monthly & Annual by District
Estimate daily, monthly, and annual parking costs across Las Vegas neighborhoods with event surge pricing.
Los Angeles Commute Cost Calculator — Transit vs Driving
Calculate your true monthly commuting cost in Los Angeles — transit vs. driving.
Los Angeles Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across LA neighborhoods
Louisville Commute Cost Calculator
Calculate your true monthly commuting cost in Louisville — transit vs. driving.
Louisville Cost-of-Living Index
Compare Louisville living costs (index: 88) to the US national average.
Louisville Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Louisville neighborhoods.
Miami Commute Cost Calculator
Calculate your true monthly commuting cost in Miami — transit vs. driving.
Miami Cost-of-Living Index
Compare Miami living costs (index: 123) to the US national average.
Miami Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Miami neighborhoods.
Milwaukee Commute Cost Calculator
Compare your true monthly commuting cost in Milwaukee — transit vs. driving.
Milwaukee Cost-of-Living Index
Compare Milwaukee living costs (index: 88) to the US national average
Milwaukee Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Milwaukee neighborhoods.
Minneapolis Commute Cost Calculator
Calculate your true monthly commuting cost in Minneapolis — transit vs. driving.
Minneapolis Cost-of-Living Index
Compare Minneapolis living costs (index: 106) to the US national average.
Minneapolis Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Minneapolis
Nashville Commute Cost Calculator
Compare the true monthly cost of transit vs. driving in Nashville.
Nashville Cost-of-Living Index
Compare Nashville living costs (index 108) to the US national average
Nashville Parking Cost Estimator
Estimate daily, monthly, and annual parking costs in Nashville.
New York City Commute Cost Calculator
Compare your true monthly commute cost in New York City — transit vs driving.
New York City Cost-of-Living Index
Compare New York City living costs (index 187) to the US average
New York City Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across New York City.
Philadelphia Commute Cost Calculator
Compare your true monthly Philadelphia commute cost — SEPTA transit vs. driving.
Philadelphia Cost-of-Living Index
Compare Philadelphia living costs (index: 101) to the US national average
Philadelphia Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Philadelphia neighborhoods.
Phoenix Commute Cost Calculator
Calculate your true monthly commuting cost in Phoenix — transit vs. driving
Phoenix Cost-of-Living Index
Compare Phoenix living costs (index 103) to the US national average
Phoenix Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Phoenix neighborhoods
Portland Commute Cost Calculator
Calculate your true monthly commuting cost in Portland — transit vs. driving
Portland Cost-of-Living Index
Compare Portland living costs to the US average across six categories
Portland Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Portland neighborhoods
Sacramento Cost-of-Living Index
Compare Sacramento living costs (index: 115) to the US national average
San Antonio Commute Cost Calculator
Calculate your true monthly commuting cost in San Antonio — transit vs. driving.
San Antonio Cost-of-Living Index
Compare San Antonio living costs (index 92) to the US national average.
San Antonio Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across San Antonio neighborhoods.
San Diego Commute Cost Calculator
Compare driving vs. transit commuting costs in San Diego
San Diego Cost-of-Living Index
Compare San Diego living costs (index 161) to the US national average
San Diego Parking Cost Estimator
Estimate daily, monthly, and annual San Diego parking costs
San Francisco Commute Cost Calculator
Compare the true monthly cost of a Muni pass versus driving in San Francisco
San Francisco Cost-of-Living Index
Compare San Francisco living costs (index 194) to the US national average
San Francisco Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across San Francisco
San Jose Commute Cost Calculator
Compare your true monthly commuting cost in San Jose: transit vs. driving
San Jose Cost-of-Living Index
Compare San Jose living costs to the US national average
San Jose Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across San Jose
Seattle Commute Cost Calculator
Calculate your true monthly commuting cost in Seattle — transit vs. driving.
Seattle Cost-of-Living Index
Compare Seattle living costs to the US average and convert your salary
Seattle Parking Cost Estimator
Estimate daily, monthly, and annual parking costs across Seattle neighborhoods.
Malaysia SST Calculator (Sales and Services Tax) 2025
Add or extract Malaysia Sales and Services Tax at 8% — instant result in your browser.
Mexico IVA Calculator (Impuesto al Valor Agregado) 2025
Add or extract Mexico Impuesto al Valor Agregado at 16% — instant result in your browser.
SIP Calculator
Project the future value of a monthly SIP investment.
Hours Between Times Calculator
Duration between two clock times, with break deduction.
Road Trip Cost Calculator
Estimate the fuel cost of a journey and split it between passengers.
EV Charging Cost Calculator
Work out the cost of charging your electric car from any % to any %.
Car Depreciation Calculator
Project a car's resale value year by year using a declining-balance rate.
Grade Calculator
Add your assignments and points to get your overall grade and letter.
Final Grade Needed Calculator
Find the exact score you need on your final to hit your target grade.
Words Per Minute Typing Test
Measure your typing speed in WPM with live accuracy tracking.
UK Degree Classification Calculator
Work out your credit-weighted average and honours classification.
Spain NIF / NIE / DNI Validator
Check the control letter of a Spanish DNI, NIE or NIF instantly.
Poland PESEL Decoder
Decode date of birth, sex and check digit from a Polish PESEL.
South Africa ID Number Decoder
Decode birth date, gender and citizenship from a South African ID.
Chile RUT Validator
Verify a Chilean RUT/RUN verifier digit and get the correct one.
Leap Year Checker
Check if any year is a leap year and see why.
Day of Year Calculator
Find the ordinal day number and ISO week for any date.
Discount Stacking Calculator
Combine multiple discounts and see the true compounded saving.
Germany Steuer-ID Validator (Steuerliche Identifikationsnummer)
Check an 11-digit German Steuer-ID with the official MOD 11,10 check digit.
France NIR / Numéro de Sécurité Sociale Validator
Validate a French social-security number and decode its 13-digit structure.
Sweden Personnummer Decoder & Luhn Validator
Decode a Swedish personnummer — date of birth, gender and Luhn check digit.
Finland HETU Decoder (Henkilötunnus)
Decode a Finnish HETU — date of birth, gender and modulo-31 control character.
Denmark CPR Number Decoder
Decode a Danish CPR (personnummer) — date of birth, gender and century.
Norway Fødselsnummer Decoder
Decode a Norwegian fødselsnummer — date of birth, gender and checksum.
Belgium National Number Decoder
Decode a Belgian Rijksregisternummer — date of birth, gender, checksum.
Pakistan CNIC Validator & Decoder
Check a 13-digit Pakistani CNIC and read its province and gender digit.
Bangladesh NID Validator
Check a 10, 13 or 17-digit Bangladesh NID and read its embedded fields.
Malaysia MyKad Decoder
Decode a 12-digit MyKad — date of birth, place of birth and gender.
Thailand National ID Validator
Validate a 13-digit Thai National ID with its official mod-11 check digit.
China Resident ID Decoder & Validator
Decode an 18-character Chinese ID and verify its ISO 7064 check character.
Vietnam CCCD Decoder
Decode a 12-digit Vietnamese CCCD — province, birth year and gender.
Nigeria NIN Validator — Check Your 11-Digit NIN Format
Validate the format of a Nigerian National Identification Number offline.
Kenya National ID Validator — Check ID Number Format
Validate the format of a Kenyan national ID number offline.
Ghana Card PIN Validator — Check GHA Number Format
Validate the GHA-NNNNNNNNN-N format of a Ghana Card PIN offline.
Tanzania NIDA Number Validator & Decoder
Validate a 20-digit Tanzanian NIDA NIN and decode its date of birth.
Uganda NIN Validator & Decoder — Class, Gender & Birth Year
Validate a 14-character Ugandan NIN and decode its class, gender and birth-year digits.
Saudi Iqama & National ID Validator
Validate a 10-digit Saudi ID or Iqama with the official check-digit algorithm.
Israel Teudat Zehut (ID) Validator
Validate an Israeli Teudat Zehut number with the official checksum.
Morocco CIN / CNI Validator
Check a Moroccan CIN format and read the issuing-bureau region from the prefix.
Jordan National ID Validator
Check a 10-digit Jordanian National Number and read its generation marker.
Argentina CUIT / CUIL Decoder
Verify an Argentine CUIT/CUIL check digit and read its type prefix and DNI.
Colombia Cédula & NIT Validator
Check a Colombian cédula format and compute the NIT modulo-11 check digit.
Peru DNI Validator
Format-check a Peruvian DNI and compute its RENIEC verification digit.
Ecuador Cédula Validator
Validate an Ecuadorian cédula with the official modulo-10 algorithm.
Chile RUT / RUN Checker
Verify a Chilean RUT/RUN verifier digit with the modulo-11 algorithm.
US SSN Format Validator — Check Social Security Number Structure
Validate the structure of a US Social Security Number against SSA rules.
Australia TFN Validator — Tax File Number Checksum
Validate an Australian Tax File Number with the ATO modulus-11 checksum.
New Zealand IRD Number Validator — Check Digit Verification
Validate a New Zealand IRD number with the Inland Revenue modulus-11 check.
India Aadhaar Format Validator — Verhoeff Checksum Check
Validate the format of an Indian Aadhaar number with the Verhoeff checksum.
Chinese Zodiac Finder
Find your Chinese zodiac animal, element and yin-yang from your birth date.
Watts to Kilowatt-Hours (kWh) Calculator
Turn watts and running time into kWh — kWh = (W × hours) ÷ 1000. Free, browser-only.
Data Transfer Cost Calculator
Estimate cloud or CDN egress cost from volume, price per GB and free tier.
Gross to Net Pay Estimator
Estimate take-home pay from gross using your own deduction percentages.
Steps to Distance Calculator
Convert daily steps into kilometres, miles and estimated calories.
Modulo Calculator (Remainder)
Find a mod n — both the truncated and floored remainder conventions.
Work Hours Calculator
Add up a weekly timesheet — daily hours, breaks and optional gross pay.
Rent vs Buy Calculator
Compare the long-term cost of renting versus buying a home.
Scientific Calculator
Evaluate expressions with trig, logs, roots, powers, and factorials.
What Day Was I Born
Find out which day of the week you were born on.
Spain CIF Validator
Check the control character of a Spanish company tax ID (CIF) instantly.
Indonesia NPWP Validator
Check the structure of an Indonesian taxpayer number (NPWP) instantly.
Switzerland AHV Validator
Check the EAN-13 check digit of a Swiss AHV / AVS number instantly.
Greece AMKA Decoder
Decode the birth date and check digit of a Greek AMKA instantly.
Credit Card Payoff Calculator
How long to clear a card — and what the interest costs.
Lease vs Buy Calculator
Compare the true cost of leasing against buying with finance.
Child Height Predictor
Estimate a child's adult height from the parents' heights.
Time Until the Weekend
Live countdown to Saturday — how long until the weekend.
Parallel Resistance Calculator
Total resistance of resistors wired in parallel.
Series Resistance Calculator
Total resistance of resistors wired in series.
Power (Watts) Calculator
Electrical power from voltage, current and resistance.
Work and Power Calculator
Work W = F·d·cos θ and power P = W/t or P = F·v.
Music Interval Calculator
Transpose a frequency by any interval and see ratios in cents.
Video Bitrate Calculator
Work out video file size from bitrate and duration, or the reverse.
Cost-Plus Pricing Calculator
Set a selling price by adding a markup to your unit cost.
Hourly Rate Calculator
Convert an annual salary into an equivalent hourly rate.
Smoking Cost Calculator
See what smoking costs per day, month, year and beyond.
Slope Calculator
Slope, equation and angle of a line through two points.
Distance Between Two Points Calculator
Straight-line distance between two coordinates.
Midpoint Calculator
Find the midpoint between two coordinates.
Quarter Calculator
Find which calendar quarter a date falls in, with start and end dates.
Fiscal Year Calculator
Find the fiscal year for any date — UK, US, Australia and more.
Polynomial Roots Calculator
Find the real and complex roots of quadratic and cubic equations.
Exposure Value (EV) Calculator
Compute EV and EV100 from aperture, shutter and ISO.
F-Stop Calculator
Stops difference and light change between two apertures.
FPS Timecode Calculator
Convert HH:MM:SS:FF timecode to frames and real time.
Bitrate Calculator (Audio + Video)
Find the bitrate needed to fit a target file size.
Zakat Calculator
Work out zakat at 2.5% on wealth above the nisab threshold.
Tithe Calculator
Calculate your tithe from gross or net income at any rate.
Change Maker Calculator
Work out change owed and the fewest notes and coins to give it.
Sweat Rate Calculator
Work out how much fluid you lose during exercise.
Blood Type Inheritance Calculator
Predict a child's possible blood types from both parents.
Period & Cycle Tracker
Predict your next period, ovulation and fertile window.
Body Frame Size Calculator
Small, medium or large frame from height and wrist.
Resting Metabolic Rate Calculator
Estimate your RMR and daily calorie needs.
Semester Weeks Calculator
Count how many weeks a semester or term runs from start to end.
Time Tracker & Timesheet
Start and stop timers per project, see daily and weekly totals, export a CSV timesheet.
Rent vs Buy Comparison Calculator
Full multi-year comparison with breakeven point and net-worth chart.
Exam Time Per Question Calculator
Pace your exam — how long to spend on each question.
Group Gift Splitter
Split a group gift fairly — down to the last cent.
Road Trip Time Estimator
How long will the drive really take — with rest stops added.
Parking Cost Calculator
Find the cheapest way to pay — hourly, daily cap or weekly pass.
Grade Tracker
Track every course, weight each assignment and see the score you need on the final.
Subscription Tracker
Track every subscription, see your true monthly and yearly spend, and never miss a renewal.
Tax Bracket Visualizer
See how a progressive tax schedule splits your income — marginal vs effective, on a stacked bar.
Cap Rate Calculator
Capitalization rate from NOI and property value.
Cash-on-Cash Return Calculator
Annual cash flow as a percentage of cash invested.
Inventory Turnover Calculator
How many times you sell through stock per year.
Darts Checkout Calculator
Find a 1–3 dart finish for any score from 2 to 170.
Light Travel Time Calculator
How long light takes to cross any distance in space.
Pomodoro Estimator
Estimate how long a set of pomodoros will really take.
Cycling Power Estimator
Estimate the watts needed to ride at a given speed.
Screen Time Cost Calculator
See how many hours and how much your daily screen time really adds up to.
Travel Itinerary Planner
Plan trips day by day with timed activities, costs and a printable PDF.
Weekly Schedule Maker
Build a colour-coded weekly timetable and export it to PDF.
Bill Reminder Tracker
Track every recurring bill, see what is due, and never miss a payment.
Timesheet Maker
Log daily hours per project, see totals and billable amounts, export to CSV.
Subscription Cost Tracker
Track every subscription, see your true monthly and yearly spend, and never miss a renewal.
Portfolio Rebalancer
Turn target allocations into exact buy and sell amounts.
Project Timeline Calculator
Turn task estimates in working days into real start and finish dates.
Final Grade Calculator
Work out the exact score you need on your final exam to hit your target grade.
Semester GPA Planner
Track every semester, see your cumulative 4.0 GPA, and reverse-solve a target.
Half-Life Calculator
Solve radioactive decay for remaining amount, time or half-life — with a decay chart.
Density Calculator
ρ = m ÷ V — solve for density, mass, or volume with full unit conversion
Dew Point Calculator
Temperature + relative humidity → dew point, comfort rating, wet-bulb temp.
Force Calculator (F = ma)
Newton's second law — solve for force, mass, or acceleration with full unit handling.
Heat Index Calculator
Temperature + humidity → feels-like heat index with risk category, in °C and °F.
Wind Chill Calculator
Find the real feels-like temperature: air temp + wind speed → wind chill with frostbite risk.
Japan Consumption Tax Calculator
Add or remove Japan's 10% standard or 8% reduced consumption tax instantly.
Ten-Pin Bowling Score Calculator
Enter each roll and watch the official scorecard fill in automatically.
Cricket Net Run Rate (NRR) Calculator
Calculate your tournament NRR correctly — with the bowled-out rule applied.
Cricket Run Rate Calculator
Instantly calculate CRR and RRR — current and required run rates for any match situation.
Darts Checkout Calculator
Find every valid finish for any score from 2 to 170.
Golf Handicap Calculator
Score differentials and Handicap Index using the World Handicap System (WHS).
Race Time Predictor
Predict finish times across every distance from one known race result.
Run/Walk Interval Calculator
Plan your run-walk intervals, find your effective pace and finish time.
Resting Metabolic Rate Calculator
Five peer-reviewed equations, macro splits, formula working — all in your browser.
Watts per kg Calculator
Find your cycling W/kg and Coggan category in seconds.
Body Frame Size Calculator
Determine your skeletal frame size and ideal body weight range instantly.
Doubling Time Calculator
How long until your money, population, or investment doubles?
Drone Flight Time Calculator
Physics-based flight time from battery, mass, rotors and altitude.
Country Plug Type Finder
Instantly look up the plug type, voltage and frequency for any country.
Name Day Finder
Find the name day for any first name — or discover which names are celebrated on any date.
What Time Is It In…?
Instant live clock for any city or country — runs entirely in your browser.
Zodiac Sign Calculator
Find your Western zodiac sign, element, quality and ruling planet from your birthday.
Chinese Zodiac Calculator
Find your animal sign, element, Yin/Yang polarity and lucky attributes from your birth date.
Country Dialing Code Lookup
Find any country dialing code instantly and convert local numbers to international format.
Country Driving Side Lookup
Instantly check whether any country drives on the left or right side of the road.
Mixed Number Calculator
Add, subtract, multiply and divide mixed numbers with full working shown.
Time Zone Difference Calculator
Compare the current time (or any custom time) across multiple time zones instantly.
Frequently asked questions
Are these calculators really free?
Yes. Every calculator on Gera Tools is free to use with no account, no trial and no usage limit. The site is supported by unobtrusive ads, not subscriptions.
Do my numbers get sent to a server?
No. Each calculator runs 100% client-side in your browser using JavaScript. The values you type are never transmitted, stored or logged, so they are safe for private financial, health or business figures.
How accurate are the results?
Each calculator uses the exact published formula for its field — amortisation maths for loans, the Mifflin-St Jeor equation for calories, real tax bands for take-home pay, and so on — and most show the working so you can verify it.
Can I use them on my phone?
Yes. Every tool is mobile-friendly and keeps working offline once the page has loaded, because the calculation happens on your device rather than on a server.