Percent Difference Calculator and Tutorial

Percent difference is a comparison of two values of the same measurement. Calculate the difference between two values by entering them below and see the steps used to solve.


Difference of 75 and 100 is 28.571%

Start with the formula to calculate difference percentage
|a - b|
(a + b) ÷ 2
Substitute values in the equation
|75 - 100|
(75 + 100) ÷ 2
Simplify and solve
(175) ÷ 2

How to Find Percent Difference

The percentage difference of two values can be found by dividing the difference between the values by the average of the values and then multiplying by 100 to get a percentage. The formula for percent difference is:

p = |a – b| ÷ ((a + b) ÷ 2) × 100

Our percent change calculator will also help solve the amount of change between 2 values.

Graph of percentage difference

Find the Difference

The first step in solving percent difference is to find the difference between the values. This is as simple as subtracting one value from the other. The key is to use the absolute value of the difference, which just means to drop the negative sign in front of the number if there is one.

Find the Average

The second step in calculating percent difference is to find the average of the values. To do this, add the values together to get the sum then divide by 2; this is the average.

Divide the Difference by the Average

The next step is to divide the difference of the values by the average. This is the percent difference expressed as a decimal or fraction. To convert to percentage form multiply by 100.

Example: Find the percent difference of 25 and 48

p = |25 – 48| ÷ ((25 + 48) ÷ 2) × 100
p = |-23| ÷ (73 ÷ 2) × 100
p = 23 ÷ 36.5 × 100
p = 63.014%

The calculator above simplifies finding percentage difference but it uses the formula shown to solve it. Use our percentage calculators for more tools for calculating percent values.