Percent Difference Calculator
Compare two values when neither one is the "starting" value, such as two measurements, two prices from different stores, or two lab results.
| Percent difference | 66.6667% |
|---|---|
| Absolute difference | 10 |
How to use it
- Enter the two values in any order.
- Read the percent difference and the absolute gap below.
Formula
Percent difference = |A − B| ÷ ((A + B) ÷ 2) × 100
Example
Store A sells a tool for $10 and store B for $20. The gap is 10 and the average is 15, so the percent difference is 10 ÷ 15 × 100 = 66.67%. Compare that with percent change from $10 to $20, which is 100%.
Questions
When should I use percent difference instead of percent change?
Use percent change when one value clearly came first (last year vs this year). Use percent difference when the two values are peers and the order doesn't matter.
Can percent difference be over 100%?
Yes, up to 200%, when one value is much larger than the other, for example 1 and 100.
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Last reviewed 2026-10-10. Found a mistake? Tell us.