The working behind the answer
How to use this calculator
Use this tool when one value replaces another: a new price, a different quantity or a changed count. The original value is always the comparison base. The main result names the direction and shows the size of the change; the numerical change keeps its positive or negative sign.
The formula
Compare two values
Percentage change = (new − original) ÷ original × 100
A worked example
An increase from 80 to 100 is a change of 20. Divide 20 by the original 80 and multiply by 100: a 25% increase. Going back from 100 to 80 is a 20% decrease because the base has changed.
Good to know
This tool uses a positive original value and a non-negative new value. A zero starting value has no defined conventional percentage change. Negative baselines require a context-specific interpretation and are not supported here.
Common questions
Is percentage change the same as percentage-point change?
No. A rate rising from 10% to 15% has risen by 5 percentage points and by 50% relative to its original rate.
What if both values are the same?
The change is zero, so the result is 0% and the tool reports no change.