Formula Governance
Water Intake Calculator — Change Log
Every formula on HealthCalcNow is version-controlled. This page records the formula behind the Water Intake Calculator — its current version, the source it comes from, and any revision made since publication.
Current version
Reference. ~30–35 ml/kg/day fluid-needs estimate; NASEM Dietary Reference Intakes for Water, 2004 (total-water AI 3.7 L men / 2.7 L women)
Why this confidence level. No validated personal formula for water needs; individual variation is high, so this is a rough guide rather than a target.
Revision history
How we version formulas
A calculator's math lives in an isolated module with its own version number. Changing anything that affects a result — a coefficient, a category cutoff, a rounding rule, or the cited source — requires a version bump and an entry on this page. We don't silently edit formulas.
A last-reviewed date is different from a revision: it records when we last checked the formula against its published source and confirmed it still matches. A formula can be reviewed many times without changing.
We take our values from published public-health and scientific sources rather than deriving them ourselves, and we don't claim clinician review that hasn't happened. Read more in our methodology.