How old is your body really?
Pair this with the Healthspan Score Calculator
The biological age estimate tells you where you stand. The Healthspan Score breaks that down into the five pillars driving healthy aging — movement, nutrition, sleep, stress, social — so you know which lever has the highest return for your situation.
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Get the Guide →Your chronological age tells you how many years you have been alive. Your biological age tells you how those years have actually affected your body — how your cells are functioning, how much regenerative capacity you have, how close you are to age-related disease thresholds. The two numbers can differ by a decade or more in either direction. The 12-question assessment above estimates which way your lifestyle is pushing you, and which factors are driving the difference.
Action Plan
Biomarker targets table, aging accelerators checklist, the 5-pillar protocol, a 30-day habit tracker, and a testing guide you can take to your GP — in one printable PDF.
Understanding Your Score
The number above the chart is your estimated biological age based on lifestyle predictors with established research behind them. The delta — how many years above or below your chronological age — is the more meaningful number. A 45-year-old with a biological age estimate of 38 has built protective lifestyle margin. A 45-year-old at 53 has accumulated lifestyle debt that compounds with each additional year.
Aging slower than typical
Your lifestyle profile is meaningfully protective against the major drivers of biological aging. Regular exercise, adequate sleep, low stress burden, and strong social connection all directly slow the cellular processes that age the body. The factors in your “helping” column are the ones to protect — do not lose them as life gets busier.
Aging close to typical
Your lifestyle profile is roughly average for your chronological age. The “hurting” column shows you which factors have the most room to move. Choose one. Most people who try to fix everything at once fix nothing. The pillar with the largest current deficit usually returns the most per unit of effort.
Aging faster than typical
Several lifestyle factors are working against your biological age. This is not a fixed outcome — lifestyle interventions have demonstrably shifted biological age markers in trials of 8 to 12 weeks. The interventions you need are not exotic. Most are about restoring foundational habits the body needs and has been missing. The “hurting” column is your priority list.
The Five Pillars Driving Biological Age
The 12 questions in this assessment map onto five lifestyle pillars with the strongest evidence as predictors of healthspan and biological age. Two are intuitive. Three are routinely underestimated.
Movement
Cardiovascular training maintains mitochondrial function and metabolic flexibility. Strength training preserves muscle mass — the single highest-leverage tissue for healthy aging. Both are required; neither substitutes for the other.
Nutrition
Mediterranean-pattern eating is consistently associated with slower biological aging across multiple measurement methods. Ultra-processed food is associated with faster epigenetic aging independent of calorie intake.
Sleep
Sleep is when the body performs cellular repair, memory consolidation, and immune calibration. Chronic restriction below 7 hours accelerates inflammatory aging. Sleep quality matters as much as duration.
Stress
Chronically elevated cortisol promotes visceral fat accumulation, impairs insulin sensitivity, suppresses immune function, and degrades sleep architecture. Stress is biology, not just psychology.
Social Connection
The most underestimated pillar. Holt-Lunstad et al. (2010) meta-analysis found social isolation increases mortality risk comparable to smoking 15 cigarettes a day. Close relationships are biology, not luxury.
How Biological Age Is Actually Measured
This assessment is a lifestyle proxy — useful for direction and education, but distinct from the clinical methods researchers use to measure biological age directly. There are three established categories of clinical measurement, each with different strengths.
DNA methylation clocks
The most validated category. Horvath’s epigenetic clock (2013), Hannum’s blood methylation clock (2013), Levine’s PhenoAge (2018), and Lu’s GrimAge (2019) all use DNA methylation patterns at specific genomic sites to estimate biological age. GrimAge specifically predicts time to death and time to age-related disease, and has the strongest mortality predictions of any current method.
Blood biomarker panels
PhenoAge can be approximated using nine standard blood markers: albumin, creatinine, glucose, C-reactive protein, lymphocytes, mean cell volume, red cell distribution width, alkaline phosphatase, and white blood cell count. These are routinely available through standard blood work, which makes PhenoAge the most accessible clinical biological age estimate.
Composite functional measures
The DunedinPACE method (Belsky et al., 2022) measures pace of aging from a single timepoint by comparing methylation patterns to longitudinal aging trajectories. Frailty indices, grip strength, walking speed, and VO2 max are also functional proxies with established mortality predictions.
The 8 Biomarkers That Track Biological Age
If you want to move beyond lifestyle estimates into actual biomarker tracking, these are the eight markers most consistently associated with biological age in the published research. Most are available through standard blood work your GP can order — you just have to ask, because they’re not always default. Tap each marker to see optimal range, what it actually measures, and what to do if yours is off.
ApoB — Apolipoprotein B
Optimal: under 80 mg/dL (under 65 mg/dL if you have a personal or family history of cardiovascular disease)
What it measures. The particle count of cholesterol-carrying lipoproteins. Every atherogenic lipoprotein contains exactly one ApoB molecule, so ApoB measures the actual number of plaque-forming particles in your bloodstream.
Why it matters. ApoB is a stronger predictor of cardiovascular risk than LDL cholesterol alone, because two people can have the same LDL cholesterol but very different particle counts. The 2024 ESC/EAS consensus moved ApoB into the recommended lipid panel for primary prevention.
Action. Specifically ask your GP to include ApoB in your next lipid panel — it’s not always default. If elevated, the same interventions apply as for high LDL: reduce saturated fat, increase fiber, exercise, and discuss statin or PCSK9 inhibitor therapy if lifestyle alone is insufficient.
HbA1c — Glycated Hemoglobin
Optimal: under 5.4% · Pre-diabetes range begins at 5.7% · Type 2 diabetes diagnosis at 6.5%
What it measures. Your 3-month average blood glucose, captured by the percentage of haemoglobin molecules that have glucose attached to them.
Why it matters. HbA1c reflects sustained glucose exposure rather than one-time fasting glucose. Insulin resistance and glycation are central drivers of biological aging — the higher your HbA1c, the faster your tissues age through glycation end-products.
Action. Address from the diet and exercise side first: reduce ultra-processed food and added sugars, prioritise fiber and protein, walk after meals, and add resistance training. HbA1c moves measurably within 8–12 weeks of consistent change.
hsCRP — High-Sensitivity C-Reactive Protein
Optimal: under 1.0 mg/L · Moderate inflammation: 1.0–3.0 mg/L · High: above 3.0 mg/L
What it measures. Systemic low-grade inflammation. hsCRP (the high-sensitivity assay) detects much lower levels than standard CRP, which is what you want for chronic disease risk assessment.
Why it matters. Chronic inflammation drives most age-related disease — cardiovascular, neurodegenerative, metabolic, and cancer pathways all share inflammatory mechanisms. Elevated hsCRP is one of the strongest single predictors of biological age acceleration.
Action. Specifically request hsCRP, not standard CRP. If elevated, look for sources: visceral adiposity, poor sleep, ultra-processed diet, hidden infections (gum disease, sinus, UTI), or autoimmune activity. Address the cause, not the marker.
Resting Heart Rate
Optimal: 50–70 bpm for most adults · Below 60 bpm typical for cardiovascularly fit adults
What it measures. Your heart rate at complete rest — ideally measured first thing in the morning before getting out of bed.
Why it matters. Resting heart rate above 80 bpm is associated with significantly higher all-cause mortality independent of other risk factors. A lower resting heart rate reflects better cardiovascular fitness and parasympathetic nervous system tone.
Action. Regular cardiovascular exercise drops resting heart rate 1–2 bpm per month of consistent training. Track yours over time with any wearable or by manual measurement — the trend matters more than any single reading.
Blood Pressure
Optimal: under 120/80 mmHg · Elevated: 120–129 systolic · Stage 1 hypertension: 130–139/80–89
What it measures. Arterial pressure during the contraction (systolic) and relaxation (diastolic) phases of the cardiac cycle.
Why it matters. Sustained pressure above 130/80 accelerates both vascular aging and cognitive aging. It is one of the most modifiable predictors of biological age and one of the most consequential to address.
Action. Measure at home with a validated cuff (Omron or similar) for a more accurate picture than clinic readings. If consistently elevated, the highest-leverage interventions are sodium reduction, weight loss, regular exercise, stress management, and adequate sleep — in that order for most people.
VO2 Max — Cardiorespiratory Fitness
Above-average for adults 40+: over 35 ml/kg/min (women), over 42 ml/kg/min (men)
What it measures. The maximum volume of oxygen your body can use during intense exercise — the gold-standard measure of aerobic fitness.
Why it matters. VO2 max is the single strongest predictor of all-cause mortality across population studies (Mandsager et al., JAMA 2018). Moving from “below average” to “average” VO2 max produces a larger mortality reduction than nearly any other single intervention.
Action. Tested at sports medicine clinics, some fitness centres, or estimated by Apple Watch and Garmin devices. To improve: combine zone 2 cardio (3–4 days/week, 30+ minutes) with one weekly VO2 max session (4×4 intervals at 85–95% effort).
Ferritin — Iron Storage
Optimal: 50–150 ng/mL for most adults
What it measures. Your stored iron. Ferritin tells you about iron status before haemoglobin levels drop — making it the earlier marker for iron deficiency.
Why it matters. Low ferritin causes fatigue, exercise intolerance, hair loss, restless legs, and impaired thermoregulation — often without classic anemia on a standard blood count. Very high ferritin can indicate chronic inflammation or iron overload.
Action. Common in menstruating women, vegans, and endurance athletes. If low and symptomatic, oral iron supplementation works for most people; intravenous iron is needed for some. Do not supplement without testing first — iron overload has its own risks.
Fasting Glucose
Optimal: under 95 mg/dL · Pre-diabetes range: 100–125 mg/dL · Diabetes: 126+ mg/dL
What it measures. Your blood glucose after an 8-hour fast. Together with HbA1c, fasting glucose paints a picture of how your body handles blood sugar.
Why it matters. Metabolic dysfunction precedes a type 2 diabetes diagnosis by years — sometimes decades. Catching fasting glucose creeping upward early gives you the longest window to reverse course without medication.
Action. If creeping into pre-diabetes range, the same playbook applies as for HbA1c: weight loss if applicable, fiber and protein at meals, walking after eating, and resistance training. A continuous glucose monitor for 2–3 weeks can reveal your individual food responses.
Where to Go From Here
Frequently Asked Questions
What exactly is biological age?
Biological age is an estimate of how old your body actually is at the cellular and molecular level — based on inflammatory markers, DNA methylation patterns, telomere length, mitochondrial function, and similar physiological indicators. Two people of the same chronological age can have biological ages a decade or more apart depending on genetics, lifestyle, environmental exposures, and disease history. Biological age is a stronger predictor of disease risk, mortality, and healthspan than chronological age.
Is this calculator clinically validated?
The individual lifestyle factors in this assessment are all validated predictors of biological age and healthspan in the published research. The combined estimate is a directional approximation, not a clinical measurement. For a clinically validated biological age, the most accessible options are a PhenoAge calculation from standard blood work (albumin, creatinine, glucose, CRP, lymphocytes, MCV, RDW, alkaline phosphatase, WBC) or a DNA methylation test (Horvath, GrimAge, or DunedinPACE).
Can biological age actually be reversed?
The Fitzgerald et al. (2021) pilot RCT demonstrated reversal of epigenetic age by an average of 1.96 years over an 8-week diet and lifestyle intervention. Larger trials have replicated the direction if not always the magnitude. Lifestyle interventions can demonstrably slow and partially reverse measured biological age — the catch is that the changes need to be sustained, not transient. Reverting to prior habits reverses the gains.
How often should I retake this assessment?
Every 3 to 6 months if you are actively working on lifestyle changes. The point is to track direction over time, not to chase a specific number. Daily and weekly variations in this assessment are not meaningful — the questions are about sustained patterns, not yesterday’s behaviour.
Which lifestyle factor has the biggest impact?
For most adults the biggest single lever is movement — specifically resistance training combined with regular cardiovascular activity. The evidence base is the broadest, the effect sizes are the largest, and the benefit compounds across multiple aging mechanisms simultaneously. Smoking has the largest negative impact when present, but only applies to current smokers. Among modifiable positive factors, exercise is the highest-yield intervention for most people.
Does my result mean I will live longer or shorter?
A lower biological age estimate is associated with longer healthspan and reduced age-related disease risk in population studies — but individual outcomes depend on genetics, accidents, environmental exposures, and factors no calculator captures. The result is best interpreted as direction and momentum, not destiny. The value is in showing you which levers are working for you and which are working against you.
Why does the assessment cap the result at +12/-10 years?
To keep estimates defensible. Even the validated clinical biological age tests rarely show deltas larger than 15 years from chronological age. A lifestyle proxy with no biomarkers cannot honestly claim larger deltas than the gold-standard methods. The caps prevent the estimate from drifting into unscientific territory.
Can biological age tests be wrong?
Yes — biological age estimation is an evolving science, and different methods can produce different numbers for the same person. The Horvath, Hannum, PhenoAge, GrimAge, and DunedinPACE clocks all measure aging slightly differently, and reliable test-retest variance is typically 2–4 years even with gold-standard methods.
The best practice is to track direction over time using one consistent method, rather than comparing absolute numbers across different tests. A single biological age number from any tool — including this one — should be treated as one data point, not a diagnosis. The clinical picture comes from combining biomarkers, lifestyle assessment, family history, and how you actually feel.
I am chronically ill. Does this assessment apply to me?
The lifestyle factors still matter, but chronic disease, medication effects, and treatment history all influence biological age in ways this assessment cannot capture. If you have a chronic condition, the most useful next step is discussing biological age testing with your physician rather than relying on a lifestyle proxy. The pillars below are still relevant, but the estimated number will be less accurate.
Action Plan
The biomarker targets table on page 4 lists which markers to ask your GP to include in your next blood panel — ApoB, hsCRP, HbA1c, and the others standard tests routinely miss.