Everyday Math calculators

A fast, free online calculator with memory, a running history tape and full keyboard support.

Solve every percentage question — of, increase, decrease, and what-percent-of.

Find the sale price and money saved on any discount, including double discounts.

Calculate the tip and split the bill across any number of people.

Estimate the fuel cost of any trip from distance, mileage, and fuel price.

Convert length, weight, temperature, area and volume between common units.

Convert numbers to Roman numerals and Roman numerals back to numbers.

Check if a number is prime, and see its factors and prime factorization.

Find the greatest common factor and least common multiple of any numbers.

Find the square root, cube root, nth root and square of any number.

Reduce a fraction to lowest terms and see it as a decimal, mixed number and percent.

Turn any decimal into a simplified fraction, mixed number and percentage.

See the key properties of any number — parity, primality, factors, digit sum and more.

Divide two numbers and get the quotient, remainder and decimal result.

List every prime number up to a limit, and count how many there are.

Compare two fractions to see which is greater, smaller or equal.

Show the first N digits of pi and look up any decimal digit.

Estimate travel time from distance and average speed.

Convert a percentage to a decimal, a fraction and "1 in N" odds — or back.