Percentage Difference Calculator
Enter values to calculate percentage difference with a clear result.
Calculate
Enter values and select Calculate.
How it works
Percentage difference = absolute value of (first − second) ÷ ((first + second) ÷ 2) × 100. Both values must be nonnegative and not both zero.
Worked examples
- 80 and 100: 22.22%
- 40 and 60: 40%
Frequently asked questions
Is this calculator free?
Yes. You can use it without paying or creating an account.
Does it work on a phone?
Yes. The page adapts to small and large screens.
Can I enter zero?
Where zero is mathematically valid, the calculator accepts it.
What happens if I enter an invalid value?
You will see a clear message explaining what to correct.
Does the calculation run in my browser?
Yes. The calculator runs with JavaScript on your device.
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Last updated: October 17, 2026