Percentage Calculator
Four common percentage calculations in one place: what percent is X of Y, what is X% of Y, percentage change from A to B, and adding a percentage to a number. All calculations run in your browser.
Use the percentage calculator for four common operations: find what percent one number is of another, find a percentage of a value, calculate percentage change, or add a percentage to a value.
How to calculate percentages
- Choose the calculation card that matches your problem.
- Enter the two required numbers.
- Read the result as it updates and copy it when needed.
Supported percentage calculations
The tool calculates A as a percent of B, A percent of B, the percent change from A to B, and a value after adding B percent.
Calculated values are rounded to at most six decimal places for display. Invalid or non-finite results are shown as a dash.
Privacy and limitations
The calculations run in your browser. The values you enter are used only by the page to compute the displayed result and are not intentionally uploaded by this tool.
Frequently asked questions
Can it calculate percentage increase?
Yes. Use the percentage-change card with the original value first and the new value second.
Can it calculate a discount?
You can enter a negative percentage in the add-percentage card, or calculate the percentage amount separately.
Why do I see a dash?
It appears when the result is not finite, such as division by zero or incomplete input.
How many decimals are shown?
Up to six decimal places are shown, with unnecessary trailing zeros removed.
Does it change my original values?
No. It only calculates and displays a result.