Methodology

Each calculator is defined in a code registry: name, category, inputs, the formula shown in How it works, and an optional reference link. The page you see is rendered from that definition so the visible explanation matches the structured data.

Formulas and rounding

Closed-form tools use the equation printed beside the form. Browser math follows IEEE-754 floating point; displayed values are rounded for readability (typically a short significant-figure or fixed-place format in the result area). Intermediate steps in worked examples use the same formula with concrete numbers.

References

Where a page cites a source, it is usually a Wikipedia article or another well-known statement of a standard formula (for example BMI as mass over height squared, or Mifflin–St Jeor for BMR). Those links are for the conventional definition—not a claim that this site conducted original research or clinical trials.

Limits

Fitness and chemistry tools are not professional medical or laboratory advice. Finance and personal-finance tools omit taxes, fees, and product rules unless a field names them. See About for the site-wide disclaimer.

We do not stamp a “last reviewed” date unless an editor actually reviewed that page. Registry changes ship with the site deploy.