To calculate a percentage, use the Percentage Calculator for one of three questions: what is X% of Y, what percent is X of Y, or what is the percent change from X to Y. Enter the two numbers and the answer appears instantly.
Follow along with the free Percentage Calculator, which runs in your browser, or browse more tools in this category.
How to use the Percentage Calculator
- Choose the type of question: X% of Y, X is what % of Y, or percent change.
- Enter the two numbers.
- Read the result.
- Change the numbers to compare other scenarios.
Worked example
20% of 150 is 30 (150 x 0.20). 30 is 20% of 150. And going from 80 to 100 is a 25% increase, because the change of 20 divided by the starting value 80 is 0.25.
Tips and common mistakes
- Percent change is always measured against the starting value, not the ending one.
- A 50% increase followed by a 50% decrease does not return to the original number.
- Percentage points and percent are different: moving from 10% to 12% is 2 points but a 20% relative increase.
Frequently asked questions
How do I find X% of a number?
Multiply the number by X divided by 100.
How do I calculate percent change?
Subtract the old value from the new one, divide by the old value, then multiply by 100.
Is my data stored?
No. Everything is calculated in your browser.