Percentage Change Calculator
Not the Same as a Percentage Point
Percentage change measures how much a value has moved relative to where it started — a concept that gets misquoted constantly in news headlines and financial reports. A stock that goes from $50 to $65 hasn't gained "15%"; it's gained 30% of its original value. This calculator applies the correct relative formula and labels the direction (increase or decrease) explicitly, so there's no ambiguity in the result.
The Formula
Using the absolute value of the old value in the denominator means the sign of the result is driven entirely by whether the value went up or down, not by whether the starting number itself was negative.
Where This Comes Up
- Investment returns — measuring the gain or loss on a stock, fund, or property between two dates.
- Business reporting — year-over-year revenue, expense, or headcount changes.
- Weight and fitness tracking — tracking body weight or a measurement change over a training period.
- Pricing analysis — quantifying how much a price has risen or fallen since a previous check.
| Old Value | New Value | Result |
|---|---|---|
| 50 | 65 | 30% Increase |
| 80 | 60 | 25% Decrease |
| 200 | 200 | 0% No Change |
How to Use This Calculator
- Enter the Old Value (the starting point).
- Enter the New Value (the ending point).
- Select Calculate to see the percentage change and whether it's an increase or decrease.
Related Calculations
Comparing two independent values rather than a before/after pair? Use the Percentage Difference Calculator instead. For tips, discounts, and other percentage modes, see the Percentage Calculator.