Calculation standards

How we build and review calculators

A useful calculator is a small, testable model—not a promise that every real-world condition has been captured.

Scope comes first

Each tool states what it calculates, which geometries or operating modes it supports, and which decisions remain outside its scope. We withhold a result when required inputs are missing or the requested mode is unsupported.

Sources and formula ownership

Definitions, equations and safety boundaries are traced to the references shown on each page. Competitor calculators may help reveal usability gaps, but they are never treated as numerical authority. Restricted tables, licensed standards and manufacturer data are not copied into the site without an explicit right to use them.

Units, rounding and reproducibility

Calculations use full-precision values internally. Display rounding happens only after the calculation, and purchase quantities are rounded separately where the tool explicitly says so. Unit conversions are centralized and covered by automated tests.

Verification

Every published calculation engine has reference examples, boundary cases, invalid-input checks and regression tests. High-consequence tools require stronger evidence and independent professional review. If that gate is not met, the sizing or compliance result is not published.

Local processing

The calculators run in your browser. Inputs are not sent to a calculation server. Share links encode selected inputs in the URL only when a tool offers that option.