Free tools
Stop guessing. Start measuring.
Every calculator on HealthNation is built on a peer-reviewed formula and shows you the math. Optionally email yourself the result alongside a personalized plan.
Composite & decision tools
HealthNation Score
A 0–100 composite of the nine highest-leverage health levers. Track it month-to-month.
Open tool →Supplement stack builder
Pick your goals → an evidence-graded short stack. Honest about what to skip.
Open tool →GLP-1 readiness quiz
8 questions, 3 minutes. Find out whether a GLP-1 might fit your situation.
Open tool →
Single-purpose calculators
BMR calculator
Basal metabolic rate using the Mifflin–St Jeor equation.
Open tool →Protein calculator
How much protein you actually need per day, based on body weight + activity.
Open tool →Sleep debt calculator
How much sleep you owe yourself — and how long it takes to repay it.
Open tool →VO₂ max estimator
Cardiorespiratory fitness from a sub-max test or wearable data.
Open tool →Hydration calculator
Daily water needs given your weight, climate, and activity.
Open tool →Macro calculator
Protein, fat, carb targets given your goal and energy needs.
Open tool →