How SpecWhale Reviews Its Tools

How SpecWhale builds, checks, and reviews its calculators and converters, especially for finance and health tools.

Who reviews this content

SpecWhale is built and maintained by Redwan, an independent developer -- see the About page. There is no editorial staff beyond that; the process below is how a solo-maintained site keeps hundreds of formula-driven pages consistent and correct without a large team.

Where the numbers come from

Unit converters use fixed, published conversion factors from a single data file shared by every converter on the site, so the same ratio is never defined twice and cannot drift between pages. The full factor tables are public at /reference/.

Finance and health calculators

Finance and health tools use standard, named formulas (loan amortization, BMI, MET-based calorie estimates, and similar well-established methods) rather than proprietary models. Each tool's page states its formula directly above the calculator.

Build-time checks

Every formula-driven tool is executed against multiple sample inputs automatically before each deploy; a tool that throws an error on every sample input fails the build instead of shipping broken. This is a mechanical check, not a guarantee of real-world accuracy -- it catches typos and broken expressions, not domain judgment.

Corrections

If you spot a wrong formula, an outdated conversion factor, or a broken calculator, it gets fixed directly in the shared data file behind the affected page (and every sibling page using the same factor) rather than patched on one page at a time. Changes of any real substance are logged on the changelog.

Limitations

SpecWhale is a free utility reference, not professional advice. Finance, health, and legal-adjacent results are estimates built on stated assumptions. Confirm anything high-stakes with a qualified professional or an authoritative primary source before acting on it.