How to use it
Use this calculator for common percentage amounts, ratios, and before-to-after comparisons.
- Choose percentage of, ratio, or percentage change.
- Enter both finite values in the labelled order.
- Calculate and review the substituted formula with the result.
Worked example
For change, Rigula divides new minus old by the absolute old baseline.
Method and definitions
- Amount is p/100 × value; ratio is part/whole × 100.
- Signed change is (new − old) / |old| × 100 so an increase is positive and a decrease negative.
Limits and edge cases
- A zero ratio denominator or old baseline is undefined and is rejected.
- Displayed rounding does not change the internal binary floating-point result.
Privacy
All input and output stays in this tab. Rigula does not upload, store, or include it in a share URL.
Sources
