About the US version
The US section is a separate localized calculator library. It uses U.S. dollars and U.S. customary units, and country-specific calculators are built from current federal reference values. State and local rules are added separately where needed.
How calculators are prepared
The catalog combines individual calculators with automatically generated calculation templates. Validation is ongoing; publication does not mean every formula has been independently expert-reviewed.
For financial, legal, health or jurisdiction-specific calculations, confirm the assumptions and current rules before relying on an estimate.