Math calculator
Percentage Calculator
Calculate percentages, changes, increases, decreases, and original values.
Live calculation
Percent of
Results update immediately and retain up to eight decimal places.
Result
50
Percent ofChange either input to recalculate instantly.
About this tool
Solve four common percentage problems
Percentages express a part per hundred and appear in discounts, growth rates, grades, statistics, and everyday comparisons. Different questions require slightly different formulas.
Switch between percentage-of, percentage-change, adjustment, and reverse-percentage modes. Inputs and results remain visible so the relationship between the values is easy to check.
How it works
Calculate a percentage in three steps
- 1Choose a mode
Select the percentage question that matches your task.
- 2Enter two values
Provide the percentage and number, or the starting and final values.
- 3Read the result
See the answer and numerical difference update immediately.
Common questions
Percentage Calculator FAQ
How is percentage change calculated?
Subtract the starting value from the final value, divide by the absolute starting value, then multiply by 100.
What is reverse percentage?
It finds the original number before a known percentage increase or decrease produced the final value.
Can percentages be negative?
Yes. Negative values are supported when they produce a mathematically defined result.