Percentage Calculator
Runs in your browser — your data is never uploaded.
Three common percentage calculations in one tool: find X% of Y, work out what percent X is of Y, or calculate the percent increase or decrease between two numbers. Updates instantly as you type.
How to use Percentage Calculator
- 1
Choose the calculation you need from the dropdown.
- 2
Enter the two numbers.
- 3
The result updates automatically.
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Frequently asked questions
How do I find what percent one number is of another?+
Use the middle mode: it divides the first number by the second and multiplies by 100. For example, 30 out of 120 is 25%. This is the calculation for things like scores, completion rates and shares of a total.
What’s the difference between percentage points and percent change?+
A move from 10% to 15% is a 5 percentage-point rise but a 50% increase relative to the starting value. The increase/decrease mode reports the percent change; subtract the two percentages yourself for the point difference.
How is percent increase/decrease calculated?+
As ((new value − old value) / |old value|) × 100 — a positive result is an increase, a negative result is a decrease.
Is my data uploaded anywhere?+
No. The calculation runs entirely in your browser using JavaScript — nothing is sent to a server.