Math Tool
Percentage Calculator
Free percentage calculator for percent of a number, percentage change, and percent increase or decrease. Instant results, works offline, no sign-up.
How to use this percentage calculator
- 1
Choose the calculation type: X% of Y, X is what percent of Y, or percent increase/decrease.
- 2
Enter the two numbers you know.
- 3
The answer updates instantly as you type.
Frequently asked questions
▸How do I calculate a percentage of a number?
Multiply the number by the percentage divided by 100. For example, 15% of 200 is 200 × 15 ÷ 100 = 30. This tool does it for you instantly.
▸How do I calculate percentage change between two numbers?
Subtract the old value from the new value, divide by the old value, then multiply by 100. This calculator handles the formula automatically.
▸Is this percentage calculator free to use?
Yes, completely free with unlimited use. Everything runs in your browser, so there is no limit and your numbers never leave your device.