📖 Overview
Use this calculator to track progress consistently across measurement periods.
⚙️ How It Works
This measures relative movement from an old value to a new value as a percentage of the old value.
The Formula
Change % = [(New − Old) ÷ Old] × 100
| New | The new or current value |
| Old | The original or reference value |
| Change | Positive = increase, Negative = decrease |
💡A 20% gain followed by a 20% loss does not return to the original — it results in a 4% net loss. Percentage change is direction-sensitive and asymmetric.
Quick Reference
| Old Value | New Value | Change % |
|---|---|---|
| 100 | 120 | +20% |
| 100 | 80 | −20% |
| 250 | 300 | +20% |
| 1,000 | 850 | −15% |
| 50 | 100 | +100% |
Practical Tips
💡 Use consistent units for both inputs.
💡 Positive and negative values indicate direction of change.
💡 Pair this with absolute change for better context.
Frequently Asked Questions
❓ Why not only use absolute difference?
Percentage normalizes change across different base values.
❓ Can this be used for revenue or weight?
Yes, it works for any comparable numeric series.