Percentage Calculator
Three common percentage problems, solved instantly as you type.
What is X% of Y?
X is what % of Y?
% increase / decrease
How percentages work
A percentage is just a fraction of 100. "20%" means 20 per 100, or 0.20. To find a percentage of a number, multiply: X% of Y = (X ÷ 100) × Y. To find what percentage one number is of another, divide and multiply by 100: (A ÷ B) × 100.
Percentage change
Percentage change tells you how much something grew or shrank relative to its starting value: ((New − Old) ÷ Old) × 100. A positive result is an increase; a negative result is a decrease. It's perfect for price changes, growth rates, discounts and statistics.
What's the difference between percentage points and percent?
Going from 10% to 12% is a 2 percentage-point rise, but a 20% increase. They measure different things — this tool calculates the percentage change.
Is it free and private?
Yes. No sign-up, and every calculation runs locally in your browser.