ClarityHow to use this tool
- Enter original value, new value.
- Select Calculate to view the result.
- Check the method and assumptions below before using the result.
Input reference and sample values
Use the units and choices shown for each field. Sample values are provided for practice, not as recommendations.
| Input | Format and units | Sample |
|---|---|---|
| Original value | Numeric value. | 80 |
| New value | Numeric value. | 100 |
Result for these sample inputs
25 percent
- Absolute change
- 20
- Original value
- 80
Select Try the example in the form to load these values and calculate them again. This replaces the current form inputs. Compare the result with the method and worked explanation below.
The method, explained
Change (%) = (new value − original value) ÷ |original value| × 100. The absolute denominator makes the direction explicit for negative starting values.
Going from 80 to 100 is a 25% increase. Going from 100 back to 80 is a 20% decrease.
Understanding your result
The original value is the comparison baseline. Reversing the two values usually changes the percentage magnitude. A zero original value has no defined percentage change.
What to keep in mind
A zero original value has no finite percentage change. Negative starting values can be interpreted differently in financial reporting; this tool uses the absolute original value.
Common questions
Why are the increase and decrease not equal?
They use different starting values as denominators. The difference of 20 is 25% of 80 but only 20% of 100.
What if the original is zero?
Percentage change is undefined. Use the absolute change instead of a percentage.
Methodology maintained by ClarityKit. How these tools are built and checked.