Percentage Difference Calculator
Enter two values to see how far apart they are as a percentage of their average. Unlike percentage change, there is no “before” and “after” here — the two values are treated as equals, so the order you enter them doesn’t matter.
How to calculate percentage difference
Divide the absolute gap between the values by their average, then multiply by 100:
difference % = |V1 − V2| / ((V1 + V2) / 2) × 100
Because it divides by the average rather than by one specific value, swapping V1 and V2 gives the same answer.
Worked examples
- 10 and 6: |10 − 6| / 8 × 100 = 50%.
- 200 and 240: 40 / 220 × 100 ≈ 18.18%.
- 7.5 and 7.5: 0 / 7.5 × 100 = 0%.
Percentage difference table
A few value pairs and the percentage difference between them:
| Values | Difference |
|---|---|
| 8 and 12 | 40% |
| 10 and 6 | 50% |
| 100 and 110 | 9.52% |
| 200 and 240 | 18.18% |
| 50 and 100 | 66.67% |
| 5 and 15 | 100% |
| 1 and 9 | 160% |
Frequently asked questions
When should I use percentage difference instead of percentage change?
Use percentage difference when neither value is the original or the reference — for example comparing two lab measurements or two estimates. Use percentage change when one value comes before the other in time.
Why does percentage difference divide by the average?
So the result is symmetric. If it divided by one of the two values, swapping them would change the answer. Dividing by the average treats both values equally.
Can percentage difference be over 100%?
Yes, when the two values are very far apart. Comparing 10 and 90 gives |80| / 50 x 100 = 160%.