Step-by-step
- Identify the original value and the new value.
- Subtract the original from the new value.
- Divide the difference by the original value.
- Multiply by 100 to get the percentage.
- Enter the two values in the Percentage Change Calculator to check your result.
The formula
Percentage change = (new value − original value) ÷ original value × 100. A price that rises from 80 to 100 changes by (100 − 80) ÷ 80 × 100 = 25%. A price that falls from 100 to 80 changes by (80 − 100) ÷ 100 × 100 = −20%.
Why zero is a problem
If the original value is zero, the division is not possible, so the percentage change is undefined. The calculator asks for a non-zero starting value.
Change versus difference
Percentage change depends on the order of the two values. If neither value is the natural starting point, such as two measurements, the percent difference gives a symmetrical comparison using their average.
Finish the task with DevUtilityKits
Use the relevant online utility, check the result, and continue with your development workflow.
Open Percentage Change Calculator →Open Percent Difference Calculator →