Free online Percentage Change Calculator. Input original and new value, auto-calculates percentage increase or decrease. Supports positive/negative change, reverse calculation, data analysis and financial reporting. | No Sign-up · Data Never Leaves Your Device
Zero Dependencies · Works OfflineEnter original and new values to calculate percentage change
| Scenario | Original | New Value | Change |
|---|---|---|---|
| Stock Up | 50 | 65 | +30% |
| Price Drop | 200 | 160 | -20% |
| Revenue Doubled | 10000 | 20000 | +100% |
| Halved | 500 | 250 | -50% |
1. Enter the original value in the "Original Value" input box.
2. Enter the new value in the "New Value" input box.
3. Result calculates in real-time, displaying percentage change, change amount and direction.
4. Click "Swap" to quickly swap original and new value for easy bidirectional calculation.
Formula: Percentage Change = (New Value - Original) / |Original| × 100%. A positive result indicates increase, negative indicates decrease. Note that the original value cannot be zero (division by zero).
When the original value is zero, percentage change cannot be calculated (mathematically meaningless). This tool will display "Undefined". If the new value is > 0, it can be understood as an "from nothing to something" increase; in practice, use absolute change amount instead.
For example, from -50 to 50: change amount = 100, absolute original = 50, percentage change = 100/50 × 100% = +200%. This calculator uses absolute value as the denominator, correctly handling positive/negative scenarios. Suitable for profit/loss analysis, temperature change, etc.
Yes, percentage change is also commonly called growth rate (when increasing) or decline rate (when decreasing). In Excel, the equivalent formula is =(new-old)/ABS(old). In financial analysis, logarithmic returns are sometimes used as an alternative, but for daily scenarios, percentage change is sufficient.