Percentage Calculator
Calculate percentages, percentage changes, and percentage of numbers with our comprehensive percentage calculator.
Basic Percentage
What percentage is X of Y?
Results
Enter values to calculate percentage
Common Percentage Values
25%
Quarter
1/4
50%
Half
1/2
75%
Three Quarters
3/4
100%
Whole
1/1
About the percentage calculator
This page handles four common percentage questions: what percentage one value is of another, a percentage of a number, percentage change, and the basic percentage relationship.
How to use it
- Choose the tab that matches the question you are trying to answer.
- Enter the values shown by the labels; use a non-zero denominator for ratio calculations.
- Select Calculate to view the percentage or change and its supporting values.
Formula
Percentage = part ÷ whole × 100; percentage change = (new − old) ÷ old × 100
Example
20 is 25% of 80, and a change from 100 to 120 is a 20% increase.
Important notes
Percentage change uses the old value as the reference. A negative result indicates a decrease; a zero old value or whole value has no defined percentage ratio.