Fraction Calculator

To add or subtract fractions, they need a common denominator. Multiply each numerator by the other fraction's denominator, then add or subtract:

a/b + c/d = (a×d + c×b) / (b×d)

Example: 3/4 + 2/3 = (9 + 8) / 12 = 17/12, which is 1 5/12 as a mixed number, or about 1.4167.

Multiply straight across: a/b × c/d = (a×c) / (b×d). Example: 2/3 × 3/4 = 6/12 = 1/2.

Divide by multiplying by the reciprocal of the second fraction: a/b ÷ c/d = a/b × d/c. Example: 1/2 ÷ 1/4 = 1/2 × 4/1 = 2.

The calculator always reduces the answer to lowest terms by dividing the numerator and denominator by their greatest common divisor. For example, 6/12 has a greatest common divisor of 6, so it simplifies to 1/2. A negative result shows the minus sign on the numerator.

To read an improper fraction as a mixed number, divide the numerator by the denominator: 17/12 is 1 with 5 left over, so 1 5/12.