What is a Percentage Calculator?
A Percentage Calculator finds X% of a number, what percentage one number is of another, and the result of increasing or decreasing a number by a percentage.
Percentages show up in marks, discounts, interest, tax and salary hikes. Entering two numbers gives all four common answers at once.
How to use the Percentage Calculator
- Enter value X.
- Enter value Y.
- Tap Calculate to see the result.
- Tap Reset to clear the fields and try again.
Who should use it
- Students working out marks and results
- Shoppers checking discounts
- Anyone doing quick everyday sums
Key terms
- X% of Y
- The part of Y that X percent represents.
- X as a percentage of Y
- How big X is compared with Y, out of 100.
Frequently asked questions
How do I calculate a discount?
Enter the discount as X and the price as Y. “Y decreased by X%” is the price after discount.
Can I use negative numbers?
Yes.
Is my data stored?
No. Everything runs in your browser.
Last updated: 1 November 2026