What goes into every calculator and guide, where the formulas come from, and how we handle your data.
Every calculator on Vitalvalue is built on a formula published in peer-reviewed literature or widely used clinical references — the Karvonen method, the Mifflin-St Jeor equation, and standard sleep-cycle modeling among them.
Before a tool or guide goes live, it's checked for three things: does the formula match its published source, are the assumptions stated clearly, and is the margin of error disclosed rather than implied.
Reference ranges and formulas are drawn from established sources: published exercise-physiology research, national nutrition guidance, and sleep-science literature — not proprietary or unverifiable datasets.
Where a formula has known limitations for certain populations — athletes, older adults, or people with specific medical conditions — that limitation is stated next to the result, not buried in a footnote.
Guides are written to explain mechanisms — what a marker measures, why a formula is shaped the way it is — rather than to recommend specific actions. That distinction keeps the content educational rather than prescriptive, and it's why guides consistently point back to a clinician for anything individual.
Calculator inputs are processed in your browser and are not stored on our servers or shared with third parties. Contact-form submissions are used only to respond to your inquiry. We don't sell personal data, and we don't use health-related inputs for advertising.
Content is written independently of any product, supplement, or service — Vitalvalue doesn't accept sponsored placement inside guides or calculator results. When evidence on a topic is mixed, the guide says so rather than picking a side to sound more confident.
Reach the editorial desk directly — we're glad to point to the underlying reference.
Contact the desk