How it works
The difference between the new and original values is divided by the original value, then multiplied by 100. Because the original value is the base of the comparison, swapping the two values does not give the same result.
Formula: Percentage change = (new − original) ÷ original × 100
Examples
An increase
From 50 to 65 is a change of ((65 − 50) ÷ 50) × 100 = 30%.
A decrease
From 100 to 80 is a change of ((80 − 100) ÷ 100) × 100 = −20%.
Things to keep in mind
- Percentage change is directional and uses the original value as its base — it is not the same calculation as percentage difference, which treats both values symmetrically and does not care which one came first. See the Percentage Difference Calculator for that version.
- Percentage change cannot be calculated from an original value of zero, since there is nothing to compare the change to.