About the Percentage Calculator
Use this calculator to find a percentage of a number, work out what percentage one number is of another, or increase and decrease a value by a percentage. Results update instantly as you type.
How percentage calculations work
To find X% of Y, divide X by 100 and multiply by Y. To find what percentage X is of Y, divide X by Y and multiply by 100. To change a value by a percentage, multiply it by one plus the percentage expressed as a decimal.
Useful examples
- 15% of 200 = 30
- 25 is 10% of 250
- Increase 80 by 10% = 88
- Decrease 80 by 10% = 72
FAQ
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. The calculator performs this live as you type.
Does this calculator send my data anywhere?
No. The calculation runs locally in your browser.
Can I calculate percentage increase or decrease?
Yes. Use the third mode and enter a positive percentage for an increase or a negative percentage for a decrease.