Percentage change measures how much a value has increased or decreased relative to its original value. The formula is: ((New - Old) / |Old|) × 100%. A positive result means increase, negative means decrease. This is one of the most common calculations in business, finance, and data analysis.
How to Use
Enter two values:
- Old value: The original/starting value
- New value: The current/ending value
- Or use reverse mode to find a missing value
The Formula
Percentage Change = ((New Value - Old Value) / |Old Value|) × 100%
Example: Price went from $80 to $100: ((100-80)/80) × 100% = +25% increase
Common Mistakes
- Confusing percentage change with percentage point change
- Using the wrong base (dividing by new instead of old)
- A 50% increase followed by a 50% decrease ≠ original value
Step-by-Step Instructions
- 1Enter the original (old) value.
- 2Enter the new (current) value.
- 3View the percentage change.
- 4Check the formula breakdown.
- 5Use reverse mode if needed.