🔢 Number Tools
Percentage Change Calculator
Calculate percentage change, increase or decrease between two values. With negative handling. Free.
% Change
How to use the % Change
1
Percentage change formula
% change = ((New − Old) ÷ |Old|) × 100. A positive result is an increase, negative is a decrease. From 100 → 150 = +50%. From 150 → 100 = −33.3% (not −50% — the base for comparison changes when you reverse direction).
2
Common confusions
If something doubles, it's a +100% increase, not 200%. If something halves, it's a −50% decrease. You can't have less than −100% (something can't decrease by more than itself). Going from 0 is undefined — you can't divide by zero, so % change from zero has no answer.