What is percentage difference?

The gap between two values divided by their average, times 100: |a − b| ÷ ((a + b) ÷ 2) × 100. 80 and 120 differ by 40 against an average of 100, so 40%.

How is it different from percentage change?

Percentage change treats one value as the start. Percentage difference treats both alike, so it gives the same answer in either order.

When is it undefined?

When the two values average to 0 but aren't equal, such as −5 and 5.

Does my data leave the browser?

No. Everything is calculated locally.

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Percentage Calculator

First value

Second value

Percentage difference

40%

|80 − 120| ÷ ((80 + 120) ÷ 2) × 100 = 40%

Average of the two: 100

Percentage difference compares two values without calling either one the start. For a change from one to the other, use % change.

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Percent

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Percentage difference between two numbers

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Percent of, is what percent, change, difference, add or subtract, reverse and percentage points.

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Frequently asked questions

What is percentage difference?: The gap between two values divided by their average, times 100: |a − b| ÷ ((a + b) ÷ 2) × 100. 80 and 120 differ by 40 against an average of 100, so 40%.
How is it different from percentage change?: Percentage change treats one value as the start. Percentage difference treats both alike, so it gives the same answer in either order.
When is it undefined?: When the two values average to 0 but aren't equal, such as −5 and 5.
Does my data leave the browser?: No. Everything is calculated locally.

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