Free Percentage Change Calculator
Enter old and new values to get the signed percentage change — positive for growth, negative for decline — plus the absolute change and a plain-English direction.
How to Use the Percentage Change Calculator
- Enter the old value.
- Enter the new value.
- Click Calculate Change for the signed % change.
Features
Uses (new − old) / |old|, so the sign always reflects direction correctly, with guards for zero baselines and clear labeling of increase vs decrease.
Benefits & Use Cases
Analysts report period-over-period moves, investors track portfolio swings, and marketers measure campaign lifts — wherever direction matters.
Tips
Percent change is asymmetric: −50% then +50% does not return to start. For multi-period growth, multiply the factors instead of adding percents.
Frequently Asked Questions
How is percentage change calculated?
(New − old) ÷ old × 100; the sign shows increase (+) or decrease (−).
What is the difference from percent increase?
Percentage change handles both directions; percent increase assumes the new value is higher.
Can old and new be negative?
Yes — the formula uses the absolute value of the old number so direction stays meaningful.
Why is a 50% drop not reversed by a 50% rise?
Because the second percent applies to a smaller base — recovering from −50% needs +100%.
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