About the Percentage Difference Calculator
Compare two values with the percentage difference formula (difference ÷ average × 100), when neither is the reference.
Also known as: percent difference, relative difference, difference between two numbers in percent.
How to use this calculator
- Enter value a, value b.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Open “Step-by-step” to see how the answer was worked out.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
% difference = |A − B| ÷ ((A + B)/2) × 100
Worked example
Using the values pre-filled in the calculator above:
- Value A = 40
- Value B = 50
the calculator returns:
- Percentage difference: 22.2222%
- Absolute difference: 10
- Average: 45
Working
|40 − 50| ÷ ((40 + 50) ÷ 2) × 100 = 22.2222%