Percentage Calculator
Calculate percentages, percentage increases, decreases, and more. 100% free and private - all calculations happen in your browser.
Multiple Modes
Four calculation modes for all your percentage needs.
100% Private
All calculations happen in your browser. Your data stays with you.
Instant Results
Get results immediately with clear formulas and explanations.
Frequently Asked Questions
How do I calculate what percentage X is of Y?
Select "X is what % of Y" mode, enter X as the number you want to find the percentage for, and Y as the total. The formula is (X / Y) × 100.
How do I calculate X% of a number?
Select "What is X% of Y" mode, enter X as the percentage, and Y as the number. The formula is (X / 100) × Y.
How do I calculate percentage increase?
Select "Percentage Increase" mode, enter the starting value in X and the ending value in Y. The formula is ((Y - X) / X) × 100.
How do I calculate percentage decrease?
Select "Percentage Decrease" mode, enter the starting value in X and the ending value in Y. The formula is ((X - Y) / X) × 100.
What happens if I enter zero?
The calculator validates your inputs. For most calculations, zero is acceptable, but division by zero is prevented (e.g., Y cannot be zero in "X is what % of Y").
Is this calculator free to use?
Yes! This percentage calculator is 100% free with no sign-up required. All calculations happen in your browser.