Conversions & Units
259 free conversions & units tools in the Calculators & Converters collection — every one runs in your browser with no signup and no uploads. Page 2 of 3.
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
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
Ring Size Conversion Chart
Convert ring sizes between US, UK, EU, and diameter / circumference
Router Bit Speed Calculator
Find the safe RPM range for any router bit diameter to avoid over-speed
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
Shoe Size Conversion Chart
Convert shoe sizes between UK, US, EU, and CM
Sickle Cell Exchange Transfusion Volume Calculator
Calculate RBC exchange volume for HbS% reduction targets
Sidereal Time Calculator
Compute Greenwich and local sidereal time for astronomy and telescope alignment
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
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.
Speed Unit Converter (Sport Edition)
Convert speed between mph, km/h, m/s, and min/km for sport.
Sheet Metal Spring-Back Angle Calculator
Estimate the over-bend needed to compensate for spring-back in sheet metal
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
Structural Steel Beam Weight Calculator
Calculate weight of W, S, HP, C, MC, L, WT, and HSS sections by piece or total order
Support Material Weight Estimator
Estimate support structure filament weight and cost for complex prints
Swimming CSS (Critical Swim Speed) Calculator
Calculate your Critical Swim Speed from two timed efforts.
Swimming Short-Course to Long-Course Converter
Convert pool swimming times between 25m and 50m venues.
Tapping Torque Calculator
Estimate tap torque and check against material/tap-size limits to prevent breakage
Temperature Correction Derating Calculator (NEC 310.15)
Derate conductor ampacity for ambient temperatures above 30 °C using NEC correction factors
Tennis Serve Speed Converter
Convert tennis serve speed between km/h, mph, and m/s.
12-Hour and 24-Hour Time Converter
Convert times between 12-hour AM/PM and 24-hour military format
Time-Lapse Interval & Clip Length Calculator
Calculate shooting interval and total shots for any time-lapse video
TOEFL to IELTS Score Converter
Convert your TOEFL iBT score to the equivalent IELTS band.
Token Unlock Selling Pressure Estimator
Estimate sell pressure from upcoming token unlocks vs daily volume
A=432 Hz Tuning Converter
Calculate note frequencies in A=432 Hz versus standard A=440 Hz tuning
Area Unit Conversion Reference
Convert m², ft², acre, hectare, and km² instantly.
Energy Unit Conversion Reference
Convert joule, calorie, BTU, kWh, eV, and ft·lbf.
Length Unit Conversion Reference
Convert between metre, foot, inch, mile, nautical mile, and more.
Mass Unit Conversion Reference
Convert kg, lb, oz, stone, tonne, and troy ounce.
Power Unit Conversion Reference
Convert watt, kilowatt, horsepower, and BTU/h instantly.
Pressure Unit Conversion Reference
Convert Pa, bar, psi, atm, mmHg, and torr.
Speed Unit Conversion Reference
Convert m/s, km/h, mph, knots, and Mach number instantly.
Temperature Unit Conversion Reference
Convert Celsius, Fahrenheit, Kelvin, and Rankine instantly.
Volume Unit Conversion Reference
Convert litre, gallon (US/UK), pint, cup, fl oz, and cubic metre.
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
Volumetric Flow Rate Calculator
Find maximum volumetric throughput for your hotend and filament
Water Pressure Reducing Valve (PRV) Setting Calculator
Set PRV pressure for elevation change and stay within IPC code limits
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.
Aircraft Weight & Balance Calculator
Check that loaded weight and CG stay within limits across your stations
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
Wort Gravity Units & Sugar Content Calculator
Convert specific gravity to gravity points, degrees Plato, and dissolved sugar per litre.
Blood Pressure Category Calculator
Classify a blood pressure reading using the 2017 ACC/AHA categories
Pulse Pressure Calculator
Find your pulse pressure and mean arterial pressure from a BP reading
Feels Like Temperature Calculator
Combine heat, humidity and wind into one apparent temperature
CM to Feet and Inches Converter
Convert centimetres to a real height like 5 ft 7 in — not decimal feet.
Data Transfer Rate Converter
Convert between Mbps, MB/s, Gbit/s and more — with the bit-vs-byte /8.
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.
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.
Unit Price Comparison Calculator
Compare price per unit across pack sizes to find the best value.
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.