Percentage Calculator
Calculate X% of Y, find what percentage X is of Y, or calculate the percentage change between two values.
About this tool
Percentage calculations come up constantly in everyday work: discounts, growth rates, test scores, budget allocations, performance comparisons and more. This calculator handles three common scenarios in one place: finding a percentage of a number, working out what percentage one number is of another, and calculating the percentage change between two values.
How to use
Select the calculation type from the dropdown, enter your two values in the X and Y fields and click Run. The result shows the answer with two decimal places. You can switch between calculation types and rerun with the same values to compare results.
When to use this tool
Use the X% of Y mode for discounts and allocations. Use the X is what % of Y mode for working out proportions and scores. Use the % change mode for comparing values over time, such as revenue growth, price changes or performance improvements.
Privacy
Mental percentage arithmetic is error-prone, especially with non-round numbers. This tool produces accurate results instantly without the need for a separate spreadsheet or device calculator.
Frequently asked questions
What does percentage change mean?
Percentage change measures how much a value has increased or decreased relative to the starting value. A positive result means growth; a negative result means a reduction. For example, going from 100 to 125 is a 25% increase.
Can I calculate a percentage decrease?
Yes. Enter the higher value as X and the lower value as Y in the percentage change mode. The result will be a negative number reflecting the percentage decrease.
Is this the same as a percentage point difference?
No. A percentage point is an absolute difference between two percentages — for example, going from 10% to 15% is a 5 percentage point increase. A percentage change would measure that same move as a 50% increase (5/10 × 100).