Percentage Calculator
Three calculators in one: find a percentage, determine ratios, and calculate percentage change.
How to percentage calculator
- 1Choose one of the three calculation modes: find a percentage of a number, find what percent one number is of another, or calculate percentage change.
- 2Enter the required values into the input fields.
- 3View the result instantly — it updates in real time as you type.
About This Tool
A percentage calculator is an essential everyday math tool. Whether you're figuring out a discount while shopping, calculating a grade on a test, or analyzing year-over-year business growth, percentages are everywhere. This free online percentage calculator combines the three most common percentage operations into a single convenient interface.
"What is X% of Y?" helps you find a portion of a number — ideal for computing tips, taxes, or discounts. "X is what % of Y?" determines the ratio between two values as a percentage — perfect for grades, statistics, or proportions. "Percentage change from X to Y" calculates the increase or decrease between two values, commonly used in finance, analytics, and reporting. All calculations happen instantly in your browser with no server round-trip.
Frequently Asked Questions
To find X% of Y, multiply Y by X and divide by 100. For example, 15% of 200 is (200 × 15) / 100 = 30. Our calculator does this for you instantly.
Divide the part by the whole and multiply by 100. For example, 30 is (30 / 200) × 100 = 15% of 200.
Percentage change = ((New Value - Old Value) / Old Value) × 100. A positive result indicates an increase, while a negative result indicates a decrease.
Yes, completely free with no sign-up, no ads, and no usage limits. All calculations happen in your browser.