What this tool does and when to use it
Percentage difference = the gap between two numbers ÷ their average × 100. It treats both numbers as equals, so the order does not matter. If one number is the before and the other the after, you want percentage change instead.
How to calculate percentage difference
- Find the gap. Subtract the smaller number from the bigger one.
- Find the average. Add the two numbers and divide by 2.
- Divide and multiply by 100. Gap ÷ average × 100 is the percentage difference.
The percentage difference formula
Percentage difference = |A − B| ÷ ((A + B) ÷ 2) × 100. The two straight lines mean you ignore the minus sign, so the answer is always positive and comes out the same whichever number you type first. For 50 and 65 the gap is 15, the average is 57.5, and 15 ÷ 57.5 × 100 = 26.09%.
| First | Second | Percentage difference | Change, first to second |
|---|---|---|---|
| 50 | 65 | 26.09% | +30% |
| 100 | 120 | 18.18% | +20% |
| 8 | 10 | 22.22% | +25% |
| 250 | 300 | 18.18% | +20% |
| 1,200 | 1,500 | 22.22% | +25% |
| 3.5 | 4.2 | 18.18% | +20% |
Percentage difference vs percentage change
Use difference when the two numbers are equals: the price of the same TV in two shops, two lab readings, two quotes for the same job. Use change when there is a before and an after: last year's rent and this year's, a weight at the start and the end of a month. The two give different answers for the same pair. From 50 to 65 is a 30% increase, but the difference between 50 and 65 is 26.09%. For the before and after case, use the percentage increase calculator.
Percentage difference between two percentages
When both numbers are already percents, say which answer you mean. If a savings rate goes from 4% to 5%, it rose by 1 percentage point. As a percent change it rose 25% (1 ÷ 4 × 100), and the percentage difference between 4% and 5% is 22.22%. News reports usually mean points; science and lab work usually mean the difference formula.
Percentage difference in Excel and Google Sheets
- Percentage difference:
=ABS(A1-B1)/AVERAGE(A1,B1), formatted as a percentage. - Percentage change:
=(B1-A1)/A1. - Percentage points:
=B1-A1when both cells are already percents.
