Percentage Calculator
Calculate X% of Y, find what percentage X is of Y, or calculate the percentage change between two values.
Runs locally · No data sent to server · Free, no signup
About Percentage Calculator
Percentage calculations come up constantly in everyday work: discounts, growth rates, test scores, budget allocations, performance comparisons and pricing. Mental arithmetic is error-prone for non-round numbers. This calculator handles three common percentage 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 Percentage Calculator
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 all three results.
When to use this tool
Use the 'X% of Y' mode for calculating discounts, tips, tax amounts and budget allocations. Use 'X is what % of Y' for working out scores, proportions and conversion rates. Use '% change from X to Y' for comparing revenue, prices, performance metrics or any two values over time.
Privacy
Mental percentage arithmetic is slow and error-prone, especially with decimal values. This tool produces accurate results instantly without needing a separate calculator, spreadsheet or formula. All processing runs in your browser.
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 80 to 100 is a 25% increase.
Can I calculate a percentage decrease?
Yes. Use the percentage change mode and enter the higher original value as X and the lower new value as Y. The result will be negative, showing the percentage decrease.
What is the difference between percentage change and percentage point difference?
A percentage point is an absolute difference between two percentages. Going from 10% to 15% is a 5 percentage point increase. The percentage change of that same move is 50% (because 5 is 50% of 10). These are different concepts and are often confused.
How precise are the results?
Results are shown to two decimal places, which is sufficient for virtually all practical uses. The underlying calculation uses standard JavaScript floating-point arithmetic.