Compare 80 and 100
Two measurements are 80 and 100, and neither is the baseline.
Calculation: |80 − 100| ÷ ((80 + 100) ÷ 2) × 100 = 22.22%
Answer: The percentage difference is 22.22%.
Percentage Difference Calculator
Enter two values to calculate their percentage difference. This method uses the average of both values, so neither value is treated as the starting point.
Calculate percentage difference
Example: Find the percentage difference between 80 and 100
How to calculate percentage difference
Find the absolute difference between the two values. Divide that difference by their average, then multiply by 100.
Percentage difference formula
|first value − second value| ÷ ((first value + second value) ÷ 2) × 100
Percentage difference is useful when both values have equal standing. If one value is a starting point and the other is a later value, use percentage increase or percentage decrease instead.
Important: Percentage difference is not the same as
percentage increase or decrease. It uses the average of both values as
the reference point, rather than using one value as the baseline.
Examples
Compare estimates of 45 and 50
Two estimates for the same quantity are 45 and 50.
Calculation: |45 − 50| ÷ ((45 + 50) ÷ 2) × 100 = 10.53%
Answer: The percentage difference is 10.53%.
Compare scores of 72 and 90
Two test scores are 72 and 90, with no intended starting score.
Calculation: |72 − 90| ÷ ((72 + 90) ÷ 2) × 100 = 22.22%
Answer: The percentage difference is 22.22%.
Frequently asked questions
How do I calculate percentage difference?
Subtract the values and use the positive difference, divide it by the average of the two values, then multiply by 100.
What is the percentage difference between 80 and 100?
The difference is 20 and the average is 90. Divide 20 by 90 and multiply by 100, giving a percentage difference of 22.22%.
When should I use percentage difference instead of percentage change?
Use percentage difference when neither value is the original or baseline. Use percentage change when one value occurred first and the other is being compared against it.
Can percentage difference be more than 100%?
Yes. When two positive values are far apart, their difference can be greater than their average, producing a result above 100%.