From a fraction to a decimal

The top number is the numerator; the bottom number is the denominator. To convert 1/5, divide 1 by 5.

1 ÷ 5 = 0.2

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 ÷ 5) × 100 = 20%

Conversion at a glance

FractionDecimalPercent
1/50.220%

Picture the value

Imagine a whole divided into 5 equal pieces. Taking 1 of those pieces gives you 1/5 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.