Popular calculators

Four modes: X% of Y, X is what % of Y, % change, value after adding/subtracting a %

Body Mass Index from weight and height, with WHO category labels

Monthly payment, total paid, and total interest for a fixed-rate loan

Split a bill across people with a chosen tip percentage

Sale price and savings amount from original price and discount %

Future value of a deposit with optional monthly contributions and configurable compounding frequency

Basal metabolic rate (Mifflin–St Jeor) and daily calorie targets for maintenance and weight loss

All-to-all conversion between metric and imperial length units

Convert between Celsius, Fahrenheit, Kelvin, and Rankine

Exact age in years, months, days — plus total months, weeks, days, and hours lived

Weighted 4.0-scale grade point average from courses + letter grades + credits

Daily water target from body weight and exercise level, in liters, ml, cups, and fluid ounces

Add, subtract, multiply, divide two fractions — fully simplified result with decimal equivalent

Compute the square, cube, or any nth root of a number — with perfect-root detection

Exact number of days, weeks, months, and years between any two dates

Trip fuel and price total in metric (L/100 km) or US (mpg), with per-person split

Convert between yearly, monthly, biweekly, weekly, daily, and hourly pay

Solve for any one of speed, distance, or time given the other two

US Navy method from waist, neck, hip, and height (no scale needed)

Metric, US, and UK volume units — milliliters, liters, cups, pints, gallons, and more

Metric and imperial weight/mass — kg, lb, oz, g, tonnes, stones, US and UK tons

Monthly payment, total cost, and interest for any fixed-rate loan term in months

Solve ax² + bx + c = 0 with discriminant, real or complex roots

Standard ↔ scientific ↔ engineering notation, with order-of-magnitude breakdown

Central-tendency stats from a list of numbers — plus count, sum, min, max, range

Convert between seconds, minutes, hours, days, weeks, months, and years

How many liters of paint a room needs — wall area minus doors/windows × coats

Volume, weight, and 50 kg bag count for a concrete slab (with waste factor)

Solve for V, I, R, or P given any two — with power dissipation

Solve for density, mass, or volume given the other two

Margin %, markup %, and dollar profit from cost and revenue

Units (and revenue) needed to cover fixed costs given price and variable cost

Sample (n−1) and population (n) standard deviation + variance from a list

Pace per km and per mile from total time + distance, with 5K/10K/half/marathon presets

Add tax to a net amount or extract the tax already inside a gross amount (US sales tax or EU VAT)

kWh and dollars per day / month / year for any appliance