Formula
Percentage difference compares the absolute difference to the average of the two values.
percentage difference = |a - b| ÷ ((a + b) / 2) × 100
Free percentage tool
Percentage Difference Calculator
Compare two values using percentage difference. Useful when neither value is clearly the old or baseline value.
Examples
- 40 and 60: difference = 20, average = 50, percentage difference = 40%.
- 90 and 100: difference = 10, average = 95, percentage difference = 10.526%.
Frequently asked questions
Short, practical answers for this calculation.
When should I use percentage difference?
Use it when comparing two values and neither is the starting or reference value.
How is it different from percentage change?
Percentage change uses the old value as the reference. Percentage difference uses the average of both values.
Can percentage difference be negative?
No. It uses absolute difference, so it is usually positive.
What happens if both values are zero?
The average is zero, so percentage difference is undefined.
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