VARYVIA GUIDE
How to calculate percentage increase
Learn the percentage increase formula, when to use it, and how to avoid common denominator mistakes.
The formula
Percentage increase = (new value − original value) ÷ original value × 100. The original value is the denominator because the change is measured relative to where you started.
Example
A price rises from 80 to 100. The increase is 20. Divide 20 by the original 80, then multiply by 100: the percentage increase is 25%.
Common mistake
Dividing by the new value would answer a different question. Always identify the starting value before calculating a percentage change.