Percentage Difference CalculatorCalculators
The gap between two values as a percent of their average.
Percentage difference vs percentage change: which one to use
Two numbers, two formulas, and answers that can be far apart. Use percentage change when there is a before and an after, and percentage difference when the two values sit side by side with no start or end.
Same two numbers, very different answers
Take 2.6 trillion and 27.72 trillion. As a change from the smaller to the larger, that is an increase of 966.15%. As a change the other way, it is a fall of 90.62%. As a percentage difference, it is 165.7%. All three are correct, and each answers a different question.
Reports and homework mix them up all the time. A headline saying one figure is 966% higher than another and a table listing a 165.7% difference can describe the same pair of values. Pick the wrong one and your number looks either inflated or too small.
One calculator for each question
The Percentage Difference Calculator divides the gap between two values by their average, so the order of the values does not matter. It also lists the absolute gap and the percentage change in both directions, which puts all the possible answers on one screen. Both values must be 0 or more.
The Percentage Increase Calculator answers the before-and-after question. It measures growth from the original value, or raises a number by a percentage. A rise from 50 to 65 is 30%. Two 10% increases in a row add up to 21%, because the second one is worked out on the higher value. An original value of 0 has no percentage increase.
Choose between percentage difference and percentage change
- Ask whether one value came first. A price last year and this year has a start and an end. Two shops' prices on the same day do not.
- If there is a start, subtract it from the end value, divide by the start, and multiply by 100. That is the percentage change.
- If neither value is the start, subtract one from the other, drop the sign, divide by the average of the two, and multiply by 100. That is the percentage difference.
- Say which one you used when you report the number, for example "27.72 is 966% higher than 2.6" or "the two differ by 165.7%".
- Check the figure in the matching calculator.
Where both formulas run out
- A percentage change from 0 is undefined, because you cannot divide by zero.
- Percentage difference needs values of 0 or more, and it tops out at 200%, when one of the values is 0.
- A rate going from 10% to 12% is a 20% increase but only 2 percentage points. Neither calculator reports percentage points.
Frequently asked questions
What is the difference between percentage difference and percentage change?
Percentage change is measured from the starting value. Percentage difference is measured from the average of the two values, so it is the same in both directions.
What is the percentage difference between 27.72 and 2.6?
165.7%. The gap of 25.12 divided by the average of 15.16, times 100.
What is the percent of change from 2 to 1?
A decrease of 50%. The change of 1 is half of the starting value, 2.
Can a percentage change be more than 100%?
Yes. Any value that more than doubles has risen by more than 100%. Going from 2.6 to 27.72 is an increase of 966.15%.
Related tools
Tools used in this guide
Percentage Increase CalculatorCalculators
Finds the percentage increase between two values, or increases a value by P%.
