Sources Policy
How CalcBrand selects and cites the sources a calculator depends on.
When a calculator needs a source
Arithmetic that follows directly from the numbers entered — a percentage, a unit conversion, a loan payment from a stated rate — needs no external citation; the calculation is the definition. A calculator needs a source when it depends on a constant, an equation or a classification that comes from somewhere else: a published regression equation, a standard’s defined ampacity table, a government’s tax bands.
What counts as a source here
A source is recorded only when the constant in the code demonstrably comes from it. Preference goes to primary, checkable references — the original published paper or standard — over a secondary summary of it. A source’s title, publisher and year are recorded as verified; a link is included only when one was actually found and confirmed to resolve, never invented to make the citation look more complete.
Jurisdiction and time-sensitive rules
Tax bands, wiring regulations and similar jurisdiction-specific rules are not hard-coded as if one country’s figures were universal. Where a calculator depends on a rule that varies by country or changes over time, the rule is an input you supply — shown as “varies by jurisdiction” rather than presented as a fact — so the calculator cannot silently go out of date the way a bundled rate table would.
When a source cannot be verified
If a figure a calculator depends on could not be traced to a source we could actually check, the page says so directly rather than supplying a plausible-looking citation — flagged for human review in the page’s own limitations, not hidden. The wire size calculator is one example: its current-capacity figure is marked as an approximation precisely because it is not backed by a verified regulatory table.