Math & Calculators
Handy mathematical and business calculators for everyday calculations.
Free Percentage Calculator
Calculate percentages, increases, decreases, and ratios instantly.
Percent Off Calculator
Enter a price and a discount percentage to see the amount saved and the final price. Handles decimals exactly, so the numbers always add up.
Percentage Increase Calculator
Compare two values to get the absolute change and the percentage increase or decrease. Explains the formula and handles zero and negative values honestly.
Unit Converter
Convert between length, area, volume, mass, temperature, time, speed and digital storage units. Searchable units, exact factors, and no server round trip.
Ratio Calculator
Simplify ratios to their lowest terms, solve proportions for a missing value, and scale a ratio to a known quantity using exact arithmetic.
Average Calculator
Calculate the mean, median, mode, range and standard deviation of a list of numbers, with an exact sum and invalid entries reported.
Fraction Calculator
Exact fraction arithmetic with automatic simplification, mixed numbers, and recurring decimals shown exactly rather than rounded.
GCD and LCM Calculator
Find the greatest common divisor and least common multiple of two or more integers, with prime factorisations and the Euclidean steps.
Prime Number Checker
Check whether a number is prime, see its smallest factor and full factorisation, and find the next and previous primes.