Percentage difference calculator
The percentage difference calculator measures how far apart two numbers are, relative to their average — the fair way to compare when neither value is the 'original' one.
Percentage difference calculator FAQ
What is the percentage difference formula?
Take the absolute difference of the two numbers, divide by their average, and multiply by 100. Example: the percentage difference between 40 and 50 is |40−50| ÷ 45 × 100 ≈ 22.22%.
How is percentage difference different from percentage change?
Percentage change picks one value as the base; percentage difference treats both equally by dividing by the average. Use difference when there is no clear 'before and after'.
When should I use a percentage difference calculator?
Comparing two measurements, prices, or results where neither is the reference — for example two quotes, or two years' figures when you want a neutral comparison.
Can the percentage difference be over 100%?
Yes. If one number is more than three times the other, the difference exceeds 100% — for example, 10 vs 50 gives about 133.33%.
What if both numbers are zero?
The average is zero, so the calculation is undefined. Enter at least one non-zero value.