Percentage Difference Calculator
Find the percentage difference between two values relative to their average.
About Percentage Difference Calculator
Percentage difference compares two values without treating either as the 'original'. It divides the absolute difference by the average of the two absolute values and multiplies by 100. This is symmetric — swapping A and B gives the same result.
Formula
Percentage Difference
Percentage Difference = (|A − B| / ((|A| + |B|) / 2)) × 100
- A
- First value
- B
- Second value
Worked example
With the default values below, Percentage Difference Calculator returns Percentage Difference of 28.5714%. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Value A
- 30
- Value B
- 40
Results
- Percentage Difference
- 28.5714%
- Absolute Difference
- 10.0000
- Average of |A| and |B|
- 35.0000
Step by step
- 1Find absolute difference= 10
- 2Find average of absolute values= 35
- 3Divide and multiply by 100= 28.5714%
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 4 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is percentage difference different from percentage change?
Percentage change uses one value as the base (old→new). Percentage difference treats both values equally by dividing by their average, making it symmetric.
Can percentage difference exceed 200%?
Yes, when one value is zero and the other is not, the percentage difference is exactly 200%. It cannot exceed 200% for non-negative values.