Math Calculators
Percentage Difference Calculator
How far apart are two numbers, in percent — without picking one as the baseline? This symmetric measure compares prices, scores, and measurements fairly in eith
Private by design: this tool runs 100% in your browser. Nothing you enter is sent, stored, or tracked.
How to use this calculator
- Enter the first value.
- Enter the second value.
- See the percentage difference instantly — order doesn't matter.
The formula
Percentage difference = |a − b| ÷ ((a + b) ÷ 2) × 100. The result is identical whether you enter a then b or b then a.
Worked example
Comparing 50 and 60: |50 − 60| ÷ ((50 + 60) ÷ 2) × 100 = 10 ÷ 55 × 100 = 18.18% difference.
About this tool
How far apart are two numbers, in percent — without picking one as the baseline? This symmetric measure compares prices, scores, and measurements fairly in either direction.
Frequently asked questions
Difference vs. percentage change — which one?
Percentage change picks a baseline (old value) — it answers 'how much did it grow?' Percentage difference treats both values equally — it answers 'how far apart are they?' Use change for before/after, difference for comparisons.
When should I use this?
Comparing test scores, prices between stores, measurements from two instruments — anywhere neither value is the 'original'.
Can the values be negative?
The formula handles negatives mathematically, but interpret carefully: with values on opposite sides of zero, the result can exceed 100% and confuse. Absolute differences are usually clearer there.
Why divide by the average?
Because neither value is the baseline, the average of the two is the neutral reference point — making the result the same whichever order you enter them.