Biological Age Calculator (Body Age Estimator).
Your calendar age is fixed. Your biological age — also called your body age or physiological age — is not. Answer 7 questions to estimate how fast your body is really aging, biological vs chronological, and find out how old your body actually is.
How do I find out how old my body is?
To find out how old you are biologically, you compare your chronological (calendar) age against markers that track real aging — sleep, aerobic fitness, diet, stress, smoking, and alcohol. This calculator scores those lifestyle inputs to estimate your biological age (also called body age or physiological age). For a lab-grade reading of your physical age, methylation-based blood panels (epigenetic clocks) measure DNA aging directly; the lifestyle estimate here is a fast, free first pass at the same question.
Frequently Asked Questions
What is my biological age?+
Your biological age (also called body age or physiological age) is an estimate of how old your body actually is, based on how fast it is aging — not the number of birthdays you have had. Two people who are both 45 on the calendar can have biological ages a decade apart depending on sleep, fitness, diet, stress, smoking, and alcohol. This calculator scores those lifestyle factors to estimate yours for free.
How do I calculate my biological age?+
The fast, free way is a lifestyle questionnaire like this one: answer questions about sleep, exercise, diet, stress, smoking, alcohol, and social connection, and the tool adjusts your calendar age up or down based on factors validated against aging research. The lab-grade way is a methylation (epigenetic) blood test that reads DNA aging directly. The questionnaire is a good first pass at the same question.
How old is my body really — am I aging faster or slower than my age?+
If your biological age comes out higher than your calendar age, your body is aging faster than average; if it comes out lower, you are aging more slowly. The gap is the useful signal: it is largely driven by modifiable habits, so an "older" result can move back down within months of changing sleep, training, and diet.
What is a biological age test?+
A biological age test estimates body age from biological markers rather than your birth date. There are two common types: lifestyle-based estimators (this tool) that score daily habits, and blood-based tests — either the Levine PhenoAge clock from a standard blood panel, or commercial methylation/epigenetic tests (e.g. TruDiagnostic, Elysium) that measure DNA aging directly.
Biological age vs chronological age — what is the difference?+
Chronological age is fixed: it is the time since you were born. Biological age is variable: it reflects the actual condition and aging rate of your cells and systems. Lifestyle, genetics, and environment make biological age drift above or below chronological age — and unlike the calendar, biological age can be improved.
Is there a free biological / body age calculator?+
Yes — this page is one. Enter your age and answer seven lifestyle questions to get a free body age estimate with no signup. For a precise, lab-confirmed reading you would add a blood-based test, but the free estimate is enough to see whether your habits are aging you faster or slower than your years.
Biological age vs PhenoAge / Levine clock — which calculator should I use?+
Use this lifestyle calculator when you want a quick, equipment-free estimate from daily habits. Use the Phenotypic Age (PhenoAge) calculator when you have a blood panel: it applies the validated Levine clock to nine lab markers (albumin, creatinine, glucose, hs-CRP, and others) for a blood-based biological age. Many people run both and compare.
What biological age means.
Chronological age is the number of years since you were born. Biological age is an estimate of how well your body is functioning compared to a reference population of the same chronological age. Two 40-year-olds with the same birthday can be 35 and 50 biologically — the gap correlates with risk of cardiovascular events, cancer, and all-cause mortality more tightly than the calendar number.
The gold-standard biological age clocks (Horvath, GrimAge, PhenoAge) read DNA methylation patterns from blood. They are predictive but expensive ($200–$500/test). This calculator is a lifestyle-factor proxy — much rougher, but it surfaces the same levers that move the clinical clocks.
The levers that actually move biological age.
Across the longevity literature, four interventions show repeated, large effects on biological age estimators: aerobic fitness (VO2 max), strength and muscle mass, sleep regularity, and metabolic health (waist-to-height, fasting glucose, HbA1c, ApoB). Smoking and chronic stress move it in the opposite direction.
Of the modifiable factors, VO2 max has the strongest single association with all-cause mortality — a 1 MET (3.5 mL/kg/min) improvement maps to roughly 10–25% lower mortality risk. The fastest path to gains is structured Zone 2 plus a weekly VO2 max interval session.
How to interpret your result.
If your estimated biological age is meaningfully below your chronological age (3+ years), the protocols you are running are working — keep them. If it is above, the questionnaire flagged your highest-weight inputs (typically sleep, exercise frequency, or smoking). Treat those as the first interventions, not supplement stacks.
This calculator is an estimate, not a diagnosis. For a clinical-grade reading, methylation panels (TruDiagnostic, Elysium Index) are the current standard. Annual bloodwork (lipid panel, HbA1c, fasting insulin, ApoB, hs-CRP) is a cheaper proxy that catches most of the same trend signal.
- Levine ME, et al. (2018). An epigenetic biomarker of aging for lifespan and healthspan. Aging, 10(4), 573–591. (PhenoAge clock.)
- Lu AT, et al. (2019). DNA methylation GrimAge strongly predicts lifespan and healthspan. Aging, 11(2), 303–327.
- Mandsager K, et al. (2018). Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing. JAMA Netw Open, 1(6), e183605.
Biological age moves on every front at once — training, nutrition, and recovery. The full bundle covers all three.
Get the guide →For education, not medical advice. Results are estimates, not a diagnosis — discuss any abnormal value or health concern with a qualified clinician.
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