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Percent Difference Calculator

Calculate the symmetric percent difference between two values, using their average as the baseline.

 

 

Difference (%)

About this calculator

Use this calculator when neither number is the “true” or “starting” value: two instruments, two estimates, or two lab runs. The result is always non-negative and does not depend on which value you call A or B.

The calculation is: percent difference = |A − B| / |mean(A, B)| × 100, where mean is (A + B) / 2. The mean cannot be 0 (for example A = 5 and B = −5). Percentage change instead divides by the start only and keeps a sign.

A: First value.

B: Second value, same unit as A.

Difference (%): Symmetric absolute percent difference.