Calculate the percent difference between two values using the average-based formula, with step-by-step work.
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1. Absolute difference: |100 − 80| = 20
2. Average of the two values: (100 + 80) / 2 = 90
3. Percent difference: 20 / |90| × 100 = 22.222222 %
Also in Percentages
Arithmetic
A percent difference calculator finds the relative difference between two values using their average as the reference point. Unlike percent change, the result is the same regardless of which value is listed first, making it ideal for comparing measurements or test results.
Percent difference uses the formula |v₁ − v₂| ÷ ((v₁ + v₂) ÷ 2) × 100. The absolute value in the numerator and the average in the denominator make the calculation symmetric.
For example, comparing 100 and 80: |100 − 80| ÷ 90 × 100 ≈ 22.2%. Swapping the order gives the same result.
% diff = |v₁ − v₂| ÷ avg(v₁, v₂) × 100
Symmetric percent difference.
Frequently asked questions
Percent change uses one value as the baseline and is directional (increase vs decrease). Percent difference uses the average of both values and gives the same result regardless of order.
When both values are zero, there is no difference, so the percent difference is 0%.
Related
These related calculators come from the same leaf category, nearby sibling categories, or the same top-level topic.
Calculate the percentage difference between two values using the mean as the reference point.
Calculate the percentage increase or decrease between an old value and a new value, with the formula shown.
Calculate the percent decrease between two values, or find the new value after a given percentage decrease.
Calculate the percent increase between two values, showing the absolute difference and step-by-step work.
