Percentage Calculator
Written by Thierno Sadou Diallo, formula verified per our methodology • Last checked on 9/3/2026
To calculate X% of a number, multiply that number by X and then divide by 100. For example, 20% of 50 is calculated as: 50 × 20 ÷ 100 = 10.
Explanation
A percentage expresses a proportion out of 100: "20%" literally means "20 per 100." To find what a percentage of a given number represents, you turn the percentage into a decimal fraction (by dividing it by 100) and then multiply that fraction by the reference number. This is the most common form of percentage calculation, useful for a tip, an exam grade, or a store discount alike. If you're instead trying to find a starting number from a known part, use our total value from a percentage calculator; to track a change over time (before/after), our percentage change calculator is a better fit.
Example: calculate 20% of 50
Inputs
Reference number: 50. Percentage: 20%.
Calculation
First convert 20% to a decimal fraction: 20 ÷ 100 = 0.2. Then multiply that fraction by the reference number: 0.2 × 50 = 10.
Result
20% of 50 equals 10.
Frequently asked questions
How do I calculate a percentage quickly in my head?
For 10%, simply move the decimal point one place to the left (10% of 50 = 5). For 20%, double that result (20% of 50 = 10). For 5%, take half of 10%.
Can a percentage be greater than 100%?
Yes: a percentage greater than 100% simply means the result exceeds the reference number. For example, 150% of 40 equals 60, or one and a half times the starting value. This is common for expressing growth or exceeding a target.
What's the difference with the percentage change calculator?
This calculator answers "what is X% of Y?" — a direct calculation on a single value. The percentage change calculator answers a different question: "by what percentage did I go from one value to another?", useful for comparing a before and an after.