Guide
How to calculate percentage change without overthinking it
A plain-English explainer with the formula, a worked example, and when the result can mislead.
The short version
Percentage change compares where a value started with where it ended. The useful question is not just whether the number moved, but how large that movement is compared with the starting point.
The formula
Subtract the old value from the new value, divide that difference by the old value, then multiply by 100. A positive answer is an increase. A negative answer is a decrease.
Where it can mislead
Small starting values can make ordinary changes look dramatic. A rise from 1 to 2 is a 100% increase, but the actual change is still only 1. For money or business decisions, look at the percentage and the raw difference together.