Free Math Tools
Quick, reliable math without a spreadsheet. These free math tools handle percentages, fractions, GCD/LCM, prime numbers, roman numerals and number-to-words conversions — all in your browser.
Percentage Calculator
Work out percentages, shares and percent change.
Fraction Calculator
Add, subtract, multiply and divide fractions.
GCD Calculator
Find the greatest common divisor of any numbers.
LCM Calculator
Find the least common multiple of any numbers.
Prime Number Checker
Check if a number is prime and see its factors.
Prime Number Generator
List every prime number up to a limit.
Roman Numeral Converter
Convert numbers to Roman numerals and back.
Number to Words Converter
Spell any number out in English words.
Average Calculator
Mean, median, mode and more from a list.
Ratio Calculator
Simplify ratios and solve for a missing value.
Factorial Calculator
Compute N! exactly, even for large N.
Scientific Notation Converter
Convert between decimals and scientific notation.
Scientific Calculator
A full scientific calculator in your browser.
Math tools — questions
Are these calculators accurate?
Yes — they use precise formulas and run locally in your browser.