Percentage Calculator
Three common percentage calculations in one place: percent of a number, what percent, and percentage change.
Quick answer: To find X% of Y, multiply Y by X and divide by 100. For example, 20% of 150 is 150 × 20 ÷ 100 = 30.
What is X% of Y?
X is what percent of Y?
Percentage change from X to Y
How to use it
- Fill in the two boxes of the calculator you need.
- The answer updates as you type, in large numbers.
Percentage formulas
- X% of Y = Y × X ÷ 100
- X is what percent of Y = X ÷ Y × 100
- Percentage change = (new − old) ÷ old × 100
Quick reference
| Percent | Of 50 | Of 100 | Of 200 | Of 500 |
|---|---|---|---|---|
| 5% | 2.5 | 5 | 10 | 25 |
| 10% | 5 | 10 | 20 | 50 |
| 15% | 7.5 | 15 | 30 | 75 |
| 20% | 10 | 20 | 40 | 100 |
| 25% | 12.5 | 25 | 50 | 125 |
| 30% | 15 | 30 | 60 | 150 |
| 50% | 25 | 50 | 100 | 250 |
| 75% | 37.5 | 75 | 150 | 375 |
What people use it for
- Sales, discounts and tax
- Grades and test scores
- Pay rises and price changes
- Recipes and measurements
- Statistics and homework
Questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 80 is 80 × 15 ÷ 100 = 12.
How do I find what percent one number is of another?
Divide the first number by the second and multiply by 100. 30 out of 150 is 30 ÷ 150 × 100 = 20%.
How do I work out percentage change?
Subtract the old value from the new, divide by the old value and multiply by 100.
Is it free?
Yes. No sign-up, no install and no limit.
Is anything saved or sent?
No. Everything runs in your browser. Only your own best score, where a page shows one, is kept on your device.
Last updated 2026-10-24. Free to use, no sign-up. Made by ficklestudio26.