How this calculation works
Use this comparison when one number is the original baseline and another is the later value. A positive result indicates an increase and a negative result a decrease. The original magnitude is the denominator, so reversing the inputs changes the percentage even though the size of the numerical gap is unchanged.
Worked example
This example uses illustrative inputs. Your current result is shown above.
An original value of 100 and new value of 125 give a change of 125 − 100 = 25 and percentage change 25 ÷ 100 × 100 = 25%, an increase.
Assumptions and limits
- The original value must be nonzero; a percentage change from zero is undefined.
- Both values must use the same unit and comparable measurement periods.
- For negative baselines this tool divides by the absolute original value; interpret the signed numerical movement separately from business improvement or deterioration.
Questions people ask
Why does reversing the values not give −25%?
The reference changes. Moving from 125 to 100 loses 25 out of 125, or 20%; moving from 100 to 125 gains 25 out of 100, or 25%.
Can this measure a percentage-point change?
Enter the two rates to find their relative percentage change. Subtract the rates directly for the percentage-point gap; the two measures answer different questions.