Corrections policy

Accuracy matters

Accurate outputs matter. We welcome specific reports about formulas, constants, code, source interpretation, accessibility and written explanations.

How to report an error

Use the contact form and provide the URL, your inputs, the result shown, the result you expected and a reliable supporting source.

Our response

1. Reproduce the reported result.
2. Check the implemented formula against the cited primary source.
3. Test the correction against ordinary and boundary inputs.
4. Update the page and its reviewed date only when the change is material.
5. Add a visible correction note when the previous output could have affected an important decision.

Scope

Typographical corrections may be made without a public note when they do not change meaning. Formula, rate, regulation, unit-conversion or methodology corrections are documented and dated.