From a fraction to a decimal

The top number is the numerator; the bottom number is the denominator. To convert 1/2, divide 1 by 2.

1 ÷ 2 = 0.5

The division ends exactly, so the decimal shown is exact.

From a decimal to a percentage

A percentage measures a value out of one hundred. Multiply the decimal by 100 and write a percent sign.

(1 ÷ 2) × 100 = 50%

Conversion at a glance

FractionDecimalPercent
1/20.550%

Picture the value

Imagine a whole divided into 2 equal pieces. Taking 1 of those pieces gives you 1/2 of the whole. The shaded portion in the circle above shows this share.

Check your method

Always divide the numerator by the denominator, in that order. To turn a percentage back into a decimal, divide by 100. If you need an exact answer for a repeating value, keep the fraction instead of rounding it.