Fraction Calculator

Add, subtract, multiply, or divide two fractions. The result comes back in lowest terms, as a mixed number, and as a decimal.

Result (lowest terms)

5/6

Mixed number—

Decimal—

Steps—

How it works

Fraction arithmetic follows fixed rules. Addition and subtraction need a common denominator; multiplication and division do not. The calculator then reduces the answer by dividing the numerator and denominator by their greatest common divisor (GCD).

a/b + c/d = (a·d + c·b) / (b·d)
a/b − c/d = (a·d − c·b) / (b·d)
a/b × c/d = (a·c) / (b·d)
a/b ÷ c/d = (a·d) / (b·c)

Worked example

To add 1/2 + 1/3, use a common denominator of 6: 1/2 = 3/6 and 1/3 = 2/6, so the sum is 5/6, which is already in lowest terms.

Frequently asked questions

How do you add two fractions?

Give both a common denominator, add the numerators, then reduce: 1/2 + 1/3 = 3/6 + 2/6 = 5/6.

How do you divide fractions?

Multiply by the reciprocal of the second fraction: 1/2 ÷ 3/4 = 1/2 × 4/3 = 2/3.

What is a mixed number?

A whole number plus a proper fraction, like 1 1/3, which equals 4/3.