About Percentage Calculator
Percentages express a quantity per hundred, making differently sized totals easier to compare.
Find a percentage, percentage of a value, or percentage change. Use this page alongside your notes to check the process, then change the inputs to explore a different example.
How to use Percentage Calculator
- Review the input labels and replace the sample values with your own details.
- Check the units, options and any grading rules. The method below explains this tool’s assumptions.
- Use the action button to generate your result. Review it before copying, downloading or printing.
Method and assumptions
Choose a mode. Percentage of a value = X ÷ 100 × Y. Percentage share = X ÷ Y × 100. Percentage change = (Y − X) ÷ X × 100; the starting value must not be zero.
Worked example
20% of 150 is 30. A rise from 80 to 100 is 25%, although the numerical rise is 20.
Enter this example above, then change one input and compare the result. This helps you see which part of the method responds to the change.
Understanding your result
Read the main answer first, then review any supporting values, units or messages. An input warning means you should correct the relevant field and run the tool again.
For a useful comparison, change one input at a time and record both results. Avoid rounding intermediate values when checking calculations by hand.
Tips and common mistakes
- Do not confuse percentage points with percentage change.
- Recheck the example and input format if a result is unexpected.
- Keep a downloaded copy of work you want to reuse. Reloading the page resets your session.
Frequently asked questions
Can percentage change be negative?
Yes. A fall from 100 to 80 is −20%.
Do I need an account?
No. Use the tool directly in your browser. Inputs are kept in the current page session, so download useful work before leaving.
Can I save or print my result?
Use Copy result, Download text or Print at the bottom of Your Result. Flashcards and quizzes export their source content for reuse; citations export your edited text.