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Percent Difference Calculator

Calculate the percent difference between two numbers instantly.

Percent Difference
22.22%
Between 100 and 80

What Is Percent Difference?

Percent difference measures how different two numbers are relative to their average. It is commonly used in science, statistics, and finance to compare values.

Percent Difference Formula

Percent Difference = |A − B| / ((A + B) / 2) × 100

Unlike percent change, percent difference does not consider direction (increase or decrease). It only measures magnitude.

Percent Difference Calculator: Compare Two Numbers Easily

Whether you are analyzing lab results, comparing prices at two different stores, or evaluating statistics, calculating the gap between two numbers can get confusing. Our Percent Difference Calculator instantly finds the relative difference between two values when neither number is considered the "original" or "starting" value.

Percent Difference vs. Percent Change

It is easy to mix up these two math concepts. You should use percent change when there is a clear chronological order, such as an old price versus a new price. However, you use percent difference when the two numbers have equal standing and you just want to know how far apart they are relative to their average. For example, if two students measure the exact same tree and get slightly different heights, percent difference tells you the size of the gap between their measurements.

When to Use This Tool

  • Lab Experiments: Comparing two experimental yields or test results to see how closely they align.
  • Shopping and Finance: Comparing the cost of the exact same product from two competing retailers.
  • Quality Control: Checking the variation between the size or weight of two manufactured parts.

Percent Difference Examples

To calculate this manually, you find the absolute difference between the two numbers, divide it by their average, and multiply by 100. Our calculator does this complex math for you instantly. Here is a quick reference table showing how it works:

Value AValue BAbsolute DifferencePercent Difference
1015540%
40501022.22%
1001202018.18%

Stop wrestling with complex formulas and scratch paper. Just enter your two values into our tool above, and let it calculate the exact percentage difference in milliseconds!