Methodology and Editorial Standards

Every indexable calculator should answer four questions: what is being calculated, how it is calculated, how to check it with a realistic example, and where the method stops being reliable.

Calculation standards

Deterministic calculations are implemented from explicit formulae or transformations. Known-answer cases are used in automated regression tests. Unit conversions distinguish scale-only conversions from conversions that also require an offset.

Primary sources

Where a tool depends on an external rule rather than pure arithmetic, the page identifies the appropriate primary source category: for example HMRC/GOV.UK for UK tax rules, IETF/IANA for Internet protocols, CAA and aircraft POH/AFM material for aviation, applicable standards and manufacturer technical data for construction products.

Safety and judgement

A calculator does not replace professional judgement or approved operational data. Safety-sensitive pages state their limits explicitly. The site avoids presenting generic calculations as engineering approval, medical diagnosis, legal advice or aircraft performance approval.

Review and change control

Tool methodology is reviewed when a calculation changes, when a source rule changes, or when a reproducible error is reported. Release-level changes are recorded in the changelog.