How to Calculate Percentages

Percentage means 'per hundred.' Three common tasks: find X% of a number, find what percent X is of Y, and find the original after a percent change.

Step-by-step

1. To find X% of N: convert X to decimal (X ÷ 100), then multiply by N.
2. To find what percent X is of Y: divide X by Y, multiply by 100.
3. For percent increase: (new − old) ÷ old × 100.
4. For percent decrease: (old − new) ÷ old × 100.
5. Reverse problems: if 80 is 20% off, original = 80 ÷ 0.80 = 100.
6. Verify with our Percentage Calculator for any of these problem types.

Open the Percentage Calculator to apply these steps with your own numbers instantly.

Frequently asked questions