Calculators
Percentage Difference Calculator
Calculate the percentage difference between two values locally in your browser.
Percentage difference = |value 1 − value 2| ÷ ((value 1 + value 2) ÷ 2) × 100.
Compare two values without choosing an original value.
This calculator uses |a − b| ÷ ((a + b) ÷ 2) × 100 to show the relative difference between two values. It is different from percentage change, which uses an original value as its baseline. Your values stay in your browser and are not uploaded or stored.
Frequently Asked Questions
Everything you need to know about this tool, how it works, and privacy.
What formula does the percentage difference calculator use?
It uses percentage difference = |a − b| ÷ ((a + b) ÷ 2) × 100, where a and b are the two values. The absolute difference makes the comparison independent of order.
How is percentage difference different from percentage change?
Percentage difference treats both values equally and divides by their average. Percentage change needs a defined original value and divides the difference by that original value, so use change when direction and a starting baseline matter.
What happens if the values are equal or cannot produce a valid result?
Equal values have a percentage difference of 0%. The calculator asks for two valid numbers and cannot calculate a result when their average is zero, because that would require division by zero.
Do my values stay private?
Yes. The calculation and copy action run locally in your browser. CodeASystem does not upload or store the values you enter.