Percentage CalculatorYTScript

Percentage Difference Calculator

Measure how far two numbers sit from their average.

Runs in your browser — numbers never leave this device

Enter two numbers

Pick a question and fill both fields — the answer appears as you type.

How to use it

  1. 1

    Enter the two values in either order.

  2. 2

    Read the difference, which uses the average as the base.

  3. 3

    Check the comparison if what you actually wanted was a rise or a fall from one of the values.

Difference ignores order; change does not

Percentage difference is |A − B| / ((A + B) / 2) × 100. Switching the two numbers does not change the result. 10 and 6 differ by 50%. If you instead treat 10 as a starting point and move to 6, the decrease is 40%. Both figures are correct for their own question.

The average in the denominator can be zero — for example 5 and −5. In that case a percentage difference is not defined, and the page says so. Two zeros differ by 0%. This is not a percentile, which ranks a value inside a list of other values.

Other percentage tools

Percentage calculatorFind a percent of a number, or what percent one number is of another.Percentage increaseHow much a number rose, or add a percent to a value.Percentage decreaseHow much a number fell, or reduce a value by a percent.DiscountSale price, amount saved, or the original price.TipTip amount, total to pay, and an optional split.Test scoreTurn points scored and a total into a percentage.FractionConvert fractions, decimals, and percentages.

Frequently asked questions

What is the formula for percentage difference?

Take the absolute gap between the two numbers, divide by their average, and multiply by 100. The average is (A + B) / 2.

Why is this not the same as a percentage change?

Change picks one number as the start. Difference uses the midpoint, so it cannot tell you which way a value moved. For 100 and 200 the difference is 66.67%, the increase is 100%, and the decrease the other way is 50%.

Does the order of the two numbers matter?

No. 1.75 against 2.70 is the same difference as 2.70 against 1.75. At two decimal places that result is 42.70%.

What if the two numbers sum to zero?

Their average is zero, so the formula would divide by zero. The page reports that the difference is not defined, except when both values are zero, in which case the difference is 0%.

Is a percentage the same as a percentile?

No. A percentage is a number out of one hundred. A percentile is a rank in a list (for example, “scoring higher than 80% of the class”). This site does not compute percentiles.