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Math

Percentage Difference Calculator

Compare two values using the percentage difference formula for lab measurements and business benchmarks.

percentage differencecomparisonrelative error
Percentage Difference

Compare two measurements by dividing the absolute difference by their average.

Percentage difference
13.33%
Absolute difference
15
Mean of values
112.5

Percentage difference

Percent difference = |A − B| ÷ [(A + B) / 2] × 100

Using the average of the two values in the denominator keeps the metric symmetric regardless of which value is treated as reference.

How to use

  1. Enter the first measurement or estimate.
  2. Enter the second measurement to compare against the first.
  3. Review the absolute difference and resulting percentage difference.

Example

Input: A = 120, B = 105

Output: Percent difference ≈ 13.04%, Absolute difference = 15

FAQ & notes

How is this different from percent change?

Percent change uses one value as the baseline, while percentage difference uses the average of both values so the order does not matter.

Can I compare negative values?

Yes. The formula uses absolute values, so negative measurements work as long as both values share the same units.