Calculate percentage increase or decrease between two values, with formula and worked examples.
| Input | Result |
|---|---|
| 80 → 100 | +25% |
| 200 → 150 | −25% |
| 50 → 75 | +50% |
Subtract the old value from the new one, divide by the absolute old value, and multiply by 100.
A negative percentage means a decrease from the old value to the new value.
Using the absolute value keeps the direction of the change correct when the old value is negative.