Percentage Change Calculator
Calculate the percentage change from an original value to a new value, with direction, absolute change and multiplier.
Your inputs
Results
Percentage change
25%
- Direction
- Increase
- Absolute change
- 20
- Multiplier (new ÷ original)
- 1.25
✓Exact calculation — rounded only for display
What this calculator does
Percentage change describes how much something grew or shrank relative to where it started.
Formula and method
Change = (new − original) ÷ |original| × 100
Worked example
Calculated by this tool with its default inputs:
Inputs
- Original value: 80
- New value: 100
Results
- Percentage change: 25%
- Direction: Increase
- Absolute change: 20
- Multiplier (new ÷ original): 1.25
How to read the results
A positive result is an increase; negative is a decrease. A rise of 25 % followed by a fall of 25 % does not return to the start.
Assumptions and limitations
- Change from zero is undefined.
Questions
Why divide by the absolute value?
So that a move from −50 to −25 is correctly reported as an increase.
Methodology and verification
- Result type
- Exact mathematical calculation (rounded only for display)
- Formula version
- 1.0
- Automated verification
- 4 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
- Editorial review
- Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.
Privacy
Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy