Percentage Calculator
Calculate percentages instantly with three different modes. Find percentages of numbers, determine ratios, or calculate percentage changes.
What is X% of Y?
How to Use
- Select a calculation mode: "X% of Y" to find a percentage of a number, "X is what % of Y?" to find the percentage ratio, or "% Change" for increase/decrease.
- Enter the required values in the input fields.
- The result appears instantly as you type — no need to press a button.
- Use the result summary below the calculation for a clear explanation of the answer.
Frequently Asked Questions
How do I calculate a percentage of a number?
To find X% of Y, multiply Y by X and divide by 100. For example, 15% of 200 = 200 × 15 ÷ 100 = 30. Use our "X% of Y" mode for instant calculations.
How do I find what percentage one number is of another?
Divide the part by the whole and multiply by 100. For example, 25 is what % of 200? → (25 ÷ 200) × 100 = 12.5%. Use our "X is what % of Y?" mode.
How do I calculate percentage increase or decrease?
Subtract the old value from the new value, divide by the absolute value of the old value, and multiply by 100. For example, from 80 to 100: ((100-80) ÷ 80) × 100 = 25% increase. Use our "% Change" mode.
What's the difference between percentage and percentage points?
Percentage points describe the arithmetic difference between two percentages. For example, going from 10% to 15% is an increase of 5 percentage points, but a 50% relative increase. Our percentage change calculator computes the relative change.
Can I calculate with decimals and negative numbers?
Yes! Our calculator supports decimal numbers and negative values in all three modes. The percentage change mode correctly handles negative-to-positive transitions as well.