Percentage Difference Calculator
Find the percentage difference between two values.
Percentage difference formula
Difference % = (|V1 − V2| ÷ ((V1 + V2) ÷ 2)) × 100
This uses the average of the two values as the reference point, making it symmetrical — unlike percentage change, which always uses the original value as the base.
Note: The calculator above uses the percentage change formula (dividing by the "From" value). For true percentage difference using the midpoint average, use the formula above manually, or use Calculator 3 on the main page as an approximation when comparing similar values.
When to use percentage difference vs percentage change
- Use percentage change when one value is clearly the "original" (before/after, old/new)
- Use percentage difference when comparing two equivalent things side by side (e.g. price in two stores, measurements from two instruments)
Frequently asked questions
Percentage change uses the original value as the base (denominator). Percentage difference uses the average of the two values as the base, making it symmetrical — the percentage difference between 80 and 100 is the same as between 100 and 80.