Percentage Change Calculator
Calculate the percentage increase or decrease between two values instantly. Free percentage change calculator with formula shown.
Formula: (new − old) ÷ old × 100
Frequently asked questions
- Why is the base the old value?
- Percentage change always measures movement relative to the starting point, so the old value is the denominator.
- What if the old value is zero?
- Percentage change is undefined — dividing by zero has no meaning. Use the absolute change instead.
- Is percentage change the same as percentage points?
- No. Going from 10% to 15% is a 5 percentage point rise but a 50% relative increase.
This tool runs entirely in your browser. No data is uploaded anywhere.