How to Calculate Percentage Difference Between Two Numbers

Percentage difference helps describe how different two values are relative to their average.

It can be useful when comparing measurements, prices, experimental results, statistics, or other values where neither value is necessarily considered the original one.

Percentage Difference Formula

The formula is:

Percentage Difference = |Value 1 − Value 2| ÷ ((Value 1 + Value 2) ÷ 2) × 100

Suppose the two values are 80 and 100.

The absolute difference is:

100 − 80 = 20

Their average is:

(80 + 100) ÷ 2 = 90

Then:

(20 ÷ 90) × 100 ≈ 22.22%

The percentage difference is approximately 22.22%.