How to Calculate Percent Difference

Percent difference is a way to express the difference between two values as a percentage of their average. It is commonly used to compare two quantities and see how much they differ relative to their size.

Formula for Percent Difference

Percent Difference=∣Value 1−Value 2∣Value 1+Value 22×100%\text{Percent Difference}=\frac{|\text{Value 1}-\text{Value 2}|}{\frac{\text{Value 1}+\text{Value 2}}{2}}\times 100%Percent Difference=2Value 1+Value 2​∣Value 1−Value 2∣​×100%

Step-by-Step Calculation

1. Find the difference between the two values (take the absolute value so the result is positive):

∣Value 1−Value 2∣|\text{Value 1}-\text{Value 2}|∣Value 1−Value 2∣

2. Calculate the average of the two values:

Value 1+Value 22\frac{\text{Value 1}+\text{Value 2}}{2}2Value 1+Value 2​

3. Divide the difference by the average :

∣Value 1−Value 2∣Value 1+Value 22\frac{|\text{Value 1}-\text{Value 2}|}{\frac{\text{Value 1}+\text{Value 2}}{2}}2Value 1+Value 2​∣Value 1−Value 2∣​

4. Multiply by 100 to convert to a percentage:

×100%\times 100%×100%

Example

Suppose you want to find the percent difference between 50 and 40.

• Difference: ∣50−40∣=10|50-40|=10∣50−40∣=10
• Average: 50+402=45\frac{50+40}{2}=45250+40​=45
• Divide difference by average: 1045≈0.2222\frac{10}{45}\approx 0.22224510​≈0.2222
• Convert to percentage: 0.2222×100%=22.22%0.2222\times 100%=22.22%0.2222×100%=22.22%

Percent difference = 22.22% If you want, I can help with more examples or specific cases!