Percentage Calculator
Calculate percentages, find what percent X is of Y, compute increase/decrease, and reverse-calculate original values.
Fill in the fields to calculate
How to Use
Choose a calculation type
Select one of the four modes: basic percentage, "what percent", percentage change, or reverse percentage.
Fill in the values
Enter the numbers in the provided fields. The result updates automatically.
Copy the result
Click the copy icon next to any result to copy it.
FAQ
Multiply Y by X and divide by 100. For example, 20% of 150 = 150 × 20 ÷ 100 = 30.
Divide X by Y and multiply by 100. For example, 30 is what percent of 150? → 30 ÷ 150 × 100 = 20%.
Percentage change = ((New Value − Old Value) ÷ Old Value) × 100. A positive result means an increase; a negative result means a decrease.
Reverse percentage finds the original value before a percentage was applied. For example, if a price after a 20% increase is 120, the original price was 120 ÷ 1.20 = 100.
Results are shown to up to 6 significant figures and rounded for readability. For financial calculations requiring exact precision, verify with a dedicated tool.