Math & Algebra
169 free math & algebra tools in the Calculators & Converters collection — every one runs in your browser with no signup and no uploads. Page 1 of 2.
ACT Score Percentile Calculator
Convert your ACT composite to a national percentile.
Date Add/Subtract Duration
Add or subtract days/months/years to/from a given date
Phenytoin Free Fraction Estimator in Renal Failure
Estimate unbound phenytoin when both albumin and GFR are low
Tape Machine Operating Level Calculator
Convert between nWb/m tape flux levels and VU/dB reference levels
Sine Bar / Sine Plate Setup Calculator
Calculate gauge-block stack height for a sine bar at any angle
Aquarium Evaporation & ATO Top-Off Calculator
Estimate daily evaporation and size your ATO reservoir
Baseball Fielding Percentage Calculator
Calculate a fielder's fielding percentage with league context
Baseball On-Base Percentage Calculator
Calculate OBP, SLG, and OPS from a player's batting line.
Water-to-Grain Ratio (Quarts per Pound) Calculator
Find the optimal mash thickness for your recipe and equipment
MBEC / MBIC Ratio Calculator for Biofilm Studies
Compute biofilm eradication and inhibition ratios versus MIC
Bittering to Aroma Hop Ratio Calculator
Balance bittering, flavor, and aroma hop additions by IBU contribution
Bowling Average Calculator
Calculate your bowling average and league handicap from recent games
BU:GU Ratio Calculator
Check balance between bitterness units and gravity units in your recipe
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
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
Crop Water Use (ET) Estimator
Estimate daily and seasonal evapotranspiration for major field crops
Darts Three-Dart Average Calculator
Calculate your darts three-dart average from leg scores.
dB to Power Ratio Converter
Convert decibel values to power ratios using the 10·log10 formula.
District of Columbia Vehicle Registration Fee Calculator
Estimate your District of Columbia annual vehicle registration and excise fees.
Pharmacy Dose Rounding Calculator
Round calculated doses to the nearest available tablet or vial strength
Duration Humanizer
Convert a number of seconds into a 2 hours, 34 minutes form
E-Steps Calibration Calculator
Calculate new extruder steps-per-mm value from a calibration measurement
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
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
Fibonacci Sequence Generator
Generate the first N terms of the Fibonacci sequence
P/F Ratio (PaO₂/FiO₂) Calculator — Berlin ARDS Criteria
Calculate the oxygenation index and ARDS severity classification
Float to Rational Fraction Converter
Find the simplest rational fraction approximating a decimal
Flow Cytometry Compensation Matrix Calculator
Calculate spectral spillover correction from single-stain controls
GMAT Focus Score Percentile Calculator
Convert your GMAT Focus Edition score to a percentile.
GMAT Focus Verbal & Quant Percentile Lookup
Look up your GMAT Focus section scores as percentiles.
Grade Scale Percentage Converter
Turn one percentage mark into letter grades and GPA across 10 scales
Gravity to Degrees Balling Converter
Convert specific gravity readings to the Balling sugar scale
GRE Score Percentile Calculator
Convert GRE Verbal and Quantitative scores to percentiles.
Equipment Grounding Conductor Sizing (NEC 250.122)
Select minimum EGC wire size from the NEC 250.122 table by OCPD rating
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
Idaho Vehicle Registration Fee Calculator
Estimate your Idaho annual vehicle registration and title fees.
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
Lager Lagering Duration Calculator
Calculate minimum lagering time at temperature for clean lager production
LSAT Score Percentile Calculator
Convert your LSAT score (120-180) to a national percentile.
MCAT Score Percentile Calculator
Convert your MCAT total score to a percentile rank.
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
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.
Modular Exponentiation Calculator
Compute (base^exp) mod m efficiently using fast exponentiation
Powerlifting Total-to-Bodyweight Ratio Calculator
See how your total stacks up as a multiple of bodyweight
Primer Tm (Melting Temperature) Calculator
Estimate primer melting temperature by nearest-neighbour or basic method
Sensor Aspect Ratio to Print Size Matcher
Find standard print sizes that match your camera's native aspect ratio with the least cropping.
Ratio Simplifier
Reduce a ratio like 24:36 to its simplest form
RC Drone Thrust-to-Weight Ratio Calculator
Calculate thrust-to-weight ratio for any multirotor or fixed-wing
Chemical Reaction Theoretical & Percent Yield Calculator
Calculate theoretical yield and reaction efficiency from stoichiometry
Roman Numeral Chart
Convert integers to Roman numerals and back instantly
Extended Roman Numeral Converter
Convert numbers beyond 3999 using extended Roman numerals with vinculum overbars.
Sample Rate Conversion Ratio Calculator
Get the resampling ratio and output sample count between two rates.
SAT Math Section Score Estimator
Estimate your SAT Math section score from correct answers
SAT Score Percentile Calculator (2024 Digital SAT)
Convert your 2024 Digital SAT score to a percentile rank.
Scope 3 Business Travel Emissions Calculator
Calculate Scope 3 Category 6 business travel CO2e across all transport modes.
Soap Recipe Oil Percentage Calculator
Balance soap oil percentages for lather, hardness, and longevity
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
RPE to Percentage of Max Calculator
Convert RPE (Rate of Perceived Exertion) to % of 1RM for any lift.
Sprayer Calibration Calculator
Calibrate sprayer output in GPA from nozzle flow, speed, and row spacing
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
Tennis Serve Percentage Calculator
Calculate first-serve percentage and double fault risk
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
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.
Win Percentage Calculator
Calculate win percentage from a win, loss and tie record
Duration Converter (Days, Hours, Minutes, Seconds)
Turn a number of seconds into 1 day, 3 hours, 46 minutes, 40 seconds.
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.
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.