Is percent difference the same as percent change?
No. Percent difference compares two values against their average, so order does not matter. Percent change compares a new value against an original baseline, so order matters.
Percent Difference Calculator
Compare two measurements with symmetric percent difference, using the absolute gap divided by the average magnitude so neither value is treated as the original.
Compare two values without picking a baseline
Use percent difference when comparing two readings, estimates, quotes, lab results, or model outputs where neither value is the starting value. The order of the two values does not change the answer.
How to use it
- Enter value A.
- Enter value B.
- Review the absolute difference.
- Review the average magnitude.
- Read the symmetric percent difference.
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Symmetric percent difference
The denominator is the average magnitude of the two values, not the first value you entered.
Formula
Example
Do not confuse it with percent change
- Percent difference is symmetric and always uses the average as the denominator.
- Percent change is directional and uses an old or original baseline.
- Use percent difference for comparison; use percent change for movement over time.
FAQ
What happens if one value is zero?
If one value is zero and the other is not, the symmetric percent difference is 200%. If both values are zero, the calculation is undefined because the average magnitude is zero.
