Percent Difference Calculator

Our free online percent difference calculator helps you find the percentage difference between two positive numbers. Unlike percentage change, percent difference uses the average of the two values as the reference, making it ideal for comparing two measurements where neither is considered the "original" or "new" value.

What is Percent Difference?

Percent difference is a measure of how much two values differ from each other relative to their average. It is calculated by taking the absolute difference between the two numbers, dividing by their average, and multiplying by 100.

\[ \text{Percent Difference} = \frac{|V_1 - V_2|}{\frac{V_1 + V_2}{2}} \times 100 \]

When to Use Percent Difference

Percent difference is appropriate when:

• You want to compare two measurements of the same quantity
• Neither value is considered the "original" or "reference"
• Both values are positive numbers
• You want to know how much two values differ symmetrically

Percent Difference vs Percent Change

Percent Difference uses the average as the denominator and always gives a positive result. The order of values does not matter.

Percent Change uses the original value as the denominator and can be positive (increase) or negative (decrease). The order of values matters.

Example Calculation

What is the percent difference between 5 and 7?

\[ \frac{|5 - 7|}{\frac{5 + 7}{2}} \times 100 = \frac{2}{6} \times 100 = 33.33\% \]

So 5 and 7 have a 33.33% difference from each other. If we reversed the values (7 and 5), the result would still be 33.33%.