Percentage Calculator
Find a percentage, compare values or calculate percentage changes with instant results and clear formulas.
The interactive tool loads here when JavaScript is enabled. Files are processed locally in your browser.
How to use Percentage Calculator
- Choose one of the five calculations.
- Enter both values to see the result instantly.
- Check the formula and copy the result if needed.
Features
- Five calculations: X% of Y, X is what percent of Y, percentage increase, percentage decrease and percentage difference.
- Each mode shows its formula and a worked example.
- Signed values and scientific notation where the formula allows them.
- One-click copy of the result.
Supported formats and limitations
Input: two numbers. Output: an on-screen result with its formula.
- Use a dot as the decimal separator and no thousands separators.
Frequently asked questions
What is the difference between percentage change and percentage difference?
Percentage change compares a new value with an original one, so the direction matters. Percentage difference compares two values with their average and is the same whichever comes first.
Can the result be negative?
Yes. A decrease shown as an increase calculation returns a negative percentage, and percent-of calculations accept negative numbers.
Should I type the % sign?
No. Enter plain numbers with a decimal point; the tool adds the percent sign to the result.