Percentage Difference Calculator

Percentage difference measures how different two values are relative to their average. It is calculated as the absolute difference between the two values divided by their average, then multiplied by 100. Unlike percentage change, it does not treat either value as a reference point.

The formula is: Percentage Difference = |V1 − V2| / ((V1 + V2) / 2) × 100. You divide the absolute difference of the two values by the average of the two values, then multiply by 100 to express the result as a percentage.

No. Because the formula uses the absolute value of the difference, swapping V1 and V2 will give you the same result. This is one key distinction between percentage difference and percentage change.

Percentage change calculates how much a value has changed from a specific starting (old) value to a new value, so the order matters. Percentage difference, on the other hand, compares two values symmetrically using their average as the reference — neither value is treated as the baseline.

This calculator is designed for positive numbers greater than zero, consistent with the standard percentage difference formula. Using zero or negative numbers can produce misleading or undefined results, so it's best to use positive values only.

Use percentage difference when you want to compare two values without implying that one is the 'original' and the other is the 'new' value — for example, comparing the prices of two competing products or the test scores of two students.

A percentage difference of 0% means the two values are exactly equal. The larger the percentage difference, the more the two values diverge from each other relative to their average.

Yes. If the two values are very far apart relative to their average, the percentage difference can exceed 100%. For example, comparing 1 and 99 gives a percentage difference of about 196%.