Percent Difference Calculator

What is Percentage Difference

Though the two are often confused, percentage difference is NOT the same as percentage change!

(See our percentage change, percentage increase, and percentage decrease calculators.)

Percent difference is the percentage of the absolute difference between two numbers compared to the average of those two numbers. 

To better understand percentage difference, let's look at the formula and explain how to calculate percentage difference.

Percentage Difference Formula

Percentage Difference = (|V1 - V2| / ((V1 + V2) / 2)) * 100

How to Calculate Percentage Difference

To calculate percentage difference:

1. Find the absolute value of the difference between Value 1 (V1) and Value 2 (V2).
2. Find the average of V1 and V2 by adding V1 to V2 and dividing this sum by two.
3. Divide the absolute difference (found in step one) by the average of your two values (found in step two).
4. Multiply the result of step three by 100. The product of this is the percentage difference between your two numbers.

When finding percent difference, the order of your values does not matter because we're calculating a percentage of the absolute difference compared to the average of the two numbers.

Here's an example of calculating the percentage difference of 4 and 6:

=  ( |4 - 6| / ((4 + 6) / 2) ) * 100

= ( |-2| / (10 / 2) ) * 100

= (2 / 5) * 100

= 0.4 * 100

= 40% difference

To illustrate that the order of your values doesn't matter when calculating percent difference, here's how to find the percentage difference of 6 and 4 (switching the place of Value 1 and Value 2).

= ( |6 - 4| / (( 6 + 4) / 2) ) * 100

=  ( |2| / (10 / 2) ) * 100

= ( 2 / 5) * 100

= 0.4 * 100

= 40% difference

For other percentage calculations, like when calculating percent change, the order of your values does matter. This is because, for percent change, we're calculating the change from one number to another.