How this calculation works
The difference is compared with the magnitude of the original value. A positive result is an increase and a negative result is a decrease. A zero original value has no defined relative change.
Change (%) = (new − original) ÷ |original| × 100A worked example
Going from 100 to 125 is a 25% increase.
Good to know
Uses the stated formula and assumptions. Displayed decimal values are rounded; use consistent units for all inputs.
Going up and coming back are different percentages
A move from 100 to 150 is a 50% increase. Returning from 150 to 100 is a decrease of about 33.33%, not 50%. The starting base changes, so the same absolute difference produces a different relative change.
The same reasoning explains why a 20% fall followed by a 20% rise does not restore the starting amount. Starting at 100 gives 80 after the fall and 96 after the rise. The second percentage applies to 80.
Choose an original value that makes sense
A zero original value has no defined percentage change under this formula. There is no finite percentage multiplier that takes zero to a nonzero value. Report the absolute difference instead, or use a clearly described alternative comparison.
For a negative original value, this tool divides by its absolute magnitude. That is an explicit convention, not a universal financial reporting rule. If a report crosses from a loss to a profit, explain the underlying amounts instead of relying on the percentage alone.
A few questions, answered
Why is the result negative?
The new value is lower than the original under this signed-change convention.
Is a change from 20% to 25% just 5%?
It is five percentage points, or a 25% relative increase from the original 20% rate.