Last updated: August 15, 2026
This page describes the general process used to build and maintain calculators on Live Fitness Check. Individual calculator pages may provide additional formula, methodology, source and limitation details specific to that tool.
We aim to use established equations, reference ranges or guidance appropriate to the purpose of each calculator. When a recognized source is available, it is listed in the Sources section of the relevant calculator.
Where a calculator accepts more than one unit system, inputs are converted into the units required by the underlying formula before the result is calculated. Metric and U.S. customary inputs should represent the same underlying measurement rather than produce different mathematical rules.
Calculator implementations are checked for expected input handling, formula execution, unit conversion, invalid or missing values, result formatting and common boundary conditions. Where practical, calculated outputs are compared with independently worked examples or the expected behaviour of the documented equation.
A calculator may provide categories, ranges or explanatory text in addition to a numerical result. Those explanations are intended to help users understand the output and its limitations; they do not turn an estimate into a medical diagnosis.
Health and fitness formulas simplify real human variation. Age, sex, pregnancy, medications, medical conditions, body composition, measurement quality, training history and other factors can affect how useful an estimate is for a particular person.
Managed calculator content includes methodology, sources, limitations, disclaimers and FAQs. When this managed content is updated, the calculator page may display its most recent update date.
If you believe a calculator contains a formula, unit-conversion, wording or source error, please follow our Corrections Policy or email hello@livefitnesscheck.com.
