Percentage Difference Calculator
Calculate the percentage difference between two values relative to their average.
Formula: % diff = |a − b| / ((a + b) / 2) × 100
About Percentage Difference Calculator
Percentage Difference Calculator is a free online calculator that gives you an instant, accurate result as you type. Calculate the percentage difference between two values relative to their average.
The calculation uses the standard formula % diff = |a − b| / ((a + b) / 2) × 100 and updates live with every change to the inputs. Everything runs client-side in your browser — fast, private, and free to use as often as you like.
Unlike percent change, percentage difference is symmetric: comparing 80 to 100 gives the same result as comparing 100 to 80.
Frequently Asked Questions
Is Percentage Difference Calculator free to use?
Yes. Percentage Difference Calculator is completely free, with no sign-up, no downloads, and no usage limits. You can use it as many times as you like on any device with a web browser.
How accurate is this calculator?
The calculator applies the standard formula (% diff = |a − b| / ((a + b) / 2) × 100) with full floating-point precision and rounds only the displayed result. For most practical purposes the results are exact.
How is this different from percentage change?
Percentage change measures growth from a starting value to an ending value. Percentage difference compares two values with no direction, dividing by their average instead of one of them.
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