Free Health & Longevity Calculators.
Free, science-backed calculators to quantify and optimize your health — no account, no email, no paywall.
Each one is single-purpose and built on a metric that actually moves healthspan. Use them individually, or combine the outputs — your TDEE feeds your protein target, your Zone 2 zone feeds your VO2 trajectory, your caffeine cutoff feeds your sleep debt.
Featured.
Featured.
Four anchor tools. Pick one, get a number you can act on in under a minute.
Protein Intake Calculator
Find your optimal daily protein target based on your weight, goal, and activity level.
Zone 2 Heart Rate Calculator
Find your Zone 2 training range — the most powerful lever for metabolic health.
Biological Age Calculator
Estimate your body age from lifestyle markers and see how it compares to your calendar age.
ApoB Interpreter
Map your apolipoprotein B value to a cardiovascular risk tier and target. The single best lipid number — better than LDL when the two disagree.
The full library.
The full library.
All 35 calculators, organized by what they measure.
Nutrition
3 toolsProtein Intake Calculator
Find your optimal daily protein target based on your weight, goal, and activity level.
TDEE & Calorie Calculator
Calculate your Total Daily Energy Expenditure and ideal calorie targets for any goal.
Intermittent Fasting Calculator
Plan your intermittent fasting schedule with precise eating and fasting windows (16:8, 18:6, 20:4, OMAD).
Fitness
6 toolsZone 2 Heart Rate Calculator
Find your Zone 2 training range — the most powerful lever for metabolic health.
VO2 Max Estimator
Estimate your aerobic capacity from resting heart rate and see where you rank.
Centenarian Decathlon
Peter Attia's 10-task fitness battery from Outlive. The level you should pass at 80+ to enjoy your 90s.
Sit-to-Rise Test
Score the 10-point Brazilian sit-to-rise test and see the mortality hazard ratio from the Araújo cohort studies.
Grip Strength Percentile
See your age- and sex-adjusted grip strength percentile plus the all-cause mortality link from the Leong (Lancet) cohort.
HRV Percentile by Age
Enter your RMSSD to see how your heart rate variability ranks for your age band — and what actually moves it.
Heart
7 toolsAHA PREVENT Risk Calculator
The 2024 race-free AHA standard. Estimate 10- and 30-year cardiovascular risk per the 2026 ACC/AHA guideline.
Lp(a) Risk Interpreter
Map your lipoprotein(a) lab value to ASCVD risk tier per the 2022 EAS consensus. The single biggest blind spot in standard cholesterol panels.
hs-CRP Interpreter
Map your high-sensitivity C-reactive protein value to JUPITER-validated cardiovascular risk tiers, with acute-phase caveats.
ApoB Interpreter
Map your apolipoprotein B value to a cardiovascular risk tier and target. The single best lipid number — better than LDL when the two disagree.
Homocysteine Interpreter
Map your homocysteine to a tier linked to cardiovascular and cognitive risk — and the B-vitamin status behind it.
Metabolic Syndrome Checker
Check your five metabolic-syndrome criteria (waist, triglycerides, HDL, blood pressure, glucose) and see exactly which ones you cross. 3 of 5 = positive.
Remnant Cholesterol Calculator
The atherogenic cholesterol fraction your panel doesn't print — total minus HDL minus LDL. Predicts heart risk even when LDL is at goal.
Body Metrics
2 toolsSleep
3 toolsSleep Debt Calculator
Calculate your accumulated sleep debt over the last 7 nights and how to recover.
Caffeine Half-Life Calculator
Plot your bloodstream caffeine decay curve and find your personal cutoff time for sleep.
CBT-I Sleep Efficiency Calculator
Log a 7-day sleep diary, compute efficiency, and get the clinical sleep-restriction adjustment.
Longevity
14 toolsBiological Age Calculator
Estimate your body age from lifestyle markers and see how it compares to your calendar age.
Longevity Score
Audit your lifestyle across 6 longevity pillars and get a 0–100 healthspan score.
Peptide Reconstitution Calculator
Convert vial mg, bacteriostatic water mL, and target μg dose into exact insulin syringe units.
GKI & Autophagy Calculator
Compute your Glucose-Ketone Index and locate your stage on the 72-hour autophagy timeline.
Ferritin Interpreter
Sex- and life-stage-aware ferritin interpretation — deficiency, overload, and inflammation flagged separately.
Sauna Dose Calculator
Score your weekly sauna habit against the Finnish KIHD cohort threshold for cardiovascular and all-cause mortality reduction.
HOMA-IR Calculator
Combine fasting glucose and fasting insulin into a HOMA-IR score — the earliest reversible warning of insulin resistance, years before glucose moves.
TSH Interpreter
Map your TSH (and optional free T4) to a thyroid tier. Your lab calls a wide range "normal" — optimal is narrower.
eGFR Calculator
Estimate kidney filtration from serum creatinine, age, and sex using the 2021 race-free CKD-EPI equation, with CKD stage.
ALT & AST Interpreter
Interpret your liver enzymes against the stricter ACG healthy limit, plus what the AST/ALT ratio suggests.
Vitamin D Interpreter
See whether your 25-OH vitamin D is deficient, optimal, or in excess, with IOM and Endocrine Society thresholds. ng/mL or nmol/L.
Phenotypic Age Calculator
Turn 9 standard blood markers into your body's biological age with the validated Levine PhenoAge clock. See how many years younger or older your body is.
TyG Index Calculator
Estimate insulin resistance from fasting triglycerides and glucose — the insulin-free alternative to HOMA-IR, off any standard lipid panel.
FIB-4 Index Calculator
The first-line non-invasive screen for advanced liver fibrosis in fatty liver disease — from age, AST, ALT, and platelets. No biopsy.
How they stack.
How they stack.
The outputs feed each other. Three example chains.
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