BIOMETRIC TOOLKIT
Four calculators, plain assumptions.
Every result on this page shows the formula behind it and where that formula breaks down. Nothing here diagnoses or prescribes.
BIOMETRIC TOOLKIT
Every result on this page shows the formula behind it and where that formula breaks down. Nothing here diagnoses or prescribes.
Estimates training-intensity zones using the Karvonen method, which factors in your resting heart rate rather than age alone.
Assumes max HR ≈ 220 − age, a population average with wide individual variation. Not suitable for anyone with a diagnosed heart condition without clinical guidance.
A general daily fluid-planning estimate based on body weight, activity level and climate.
This is a planning baseline, not a medical prescription. Kidney, heart or endocrine conditions can change fluid needs significantly — confirm with a clinician if any apply.
Body mass index alongside estimated resting and total daily energy expenditure using the Mifflin–St Jeor formula.
BMI does not distinguish muscle from fat and is a screening ratio, not a diagnosis. Energy estimates are planning figures, not prescribed calorie targets.
Models how your time in bed likely splits across light, deep and REM sleep using average 90-minute cycle proportions.
This is an illustrative model, not a measurement. Only polysomnography or a validated wearable sensor can measure your actual sleep stages.
Our support desk can help you pick the right calculator or guide.
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