Percentage Calculator
Three percentage calculators in one instant tool.
This tool handles all three common percentage calculations in one place — no switching between separate tools.
Three Ways to Calculate Percentages
What is X% of Y?
Use this mode to find a percentage of a number. For example, 15% of 200 equals 30. This is handy for calculating discounts (20% off a price), sales tax, or tips on a restaurant bill. Just enter the percentage and the base number.
X is what % of Y?
Use this mode when you have two numbers and want to know the ratio as a percentage. For example, 45 out of 180 is 25%. This is useful for test scores, completion rates, or comparing a part to a whole in statistics or reports.
Percentage change from X to Y
Use this mode to find how much something increased or decreased in percentage terms. For example, going from 80 to 100 is a +25% increase. This applies to price changes, population growth, revenue comparisons, and performance tracking over time.
X% of Y = (X/100)×Y | X of Y = (X/Y)×100 | Change = ((New−Old)/Old)×100 Frequently Asked Questions
How do I calculate 20% off a price?
Select the 'What is X% of Y?' mode, enter 20 as the percentage and the original price as Y. The result is the discount amount. Subtract it from the original price to get the final price.
What is the difference between percentage and percentage points?
A percentage is a ratio out of 100. A percentage point is an absolute difference between two percentages. If a rate goes from 10% to 15%, that is a 5 percentage point increase but a 50% relative increase.
How do I find what percentage one number is of another?
Select the 'X is what % of Y?' mode, enter your part as X and the total as Y. For example, 30 out of 120 gives 25%.
How do I calculate percentage increase or decrease?
Select the 'Percentage change from X to Y' mode. Enter the old value as X and the new value as Y. A positive result means an increase, a negative result means a decrease.
Can percentage change be more than 100%?
Yes. If a value doubles, that is a 100% increase. If it triples, that is 200%. There is no upper cap on percentage increase, though percentage decrease is capped at 100% (reaching zero).
What is the formula for percentage calculations?
Three formulas: (1) X% of Y = (X / 100) × Y. (2) X is what % of Y = (X / Y) × 100. (3) Percentage change from old to new = ((New − Old) / Old) × 100.