Biological Age Calculator (PhenoAge)

PhenoAge is a biological age model developed by Dr. Morgan Levine at Yale University, published in Cell Metabolism in 2018. It uses 9 routine blood biomarkers to estimate physiological aging by predicting your mortality risk relative to the general population. Validated on over 11,000 adults from NHANES III, it outperforms simpler chronological-age-only mortality models. A PhenoAge more than 5 years below your chronological age is associated with roughly 20-30% lower all-cause mortality in population studies. It is not a clinical diagnostic tool but a validated research-grade aging biomarker.

All 9 biomarkers are available from standard blood panels ordered by your doctor. Albumin, glucose, creatinine, and alkaline phosphatase are on the Comprehensive Metabolic Panel (CMP). WBC, MCV, RDW, and lymphocyte percentage are on the Complete Blood Count with Differential (CBC with diff). CRP is ordered separately as a high-sensitivity CRP (hs-CRP) test. Most labs provide results within 24-48 hours, and many insurers cover these as part of annual preventive care.

The PhenoAge model uses the natural logarithm (ln) of CRP, not the raw value. To convert: if your CRP is 0.5 mg/L, enter ln(0.5) = -0.693. If CRP is 1.0 mg/L, enter ln(1.0) = 0. If CRP is 2.0 mg/L, enter ln(2.0) = 0.693. If CRP is 3.0 mg/L, enter ln(3.0) = 1.099. Most scientific calculators have a "ln" button. If your lab reports CRP as less than 0.3, use -1.2 as an approximation.

An elevated biological age (positive age acceleration) means your blood biomarker profile resembles that of a chronologically older person, associated with higher mortality risk and accelerated organ aging. The most common modifiable drivers include elevated fasting glucose (prediabetes or diabetes), chronic low-grade inflammation (high CRP), elevated RDW (poor red blood cell quality, often from nutritional deficiencies), low albumin (poor nutrition), and elevated WBC (chronic inflammation or infection). Lifestyle changes including Mediterranean-style diet, regular aerobic exercise, adequate sleep (7-9 hours), and stress reduction have been shown to reduce PhenoAge by 3-7 years within 6-12 months in intervention studies.

RDW (Red Cell Distribution Width) has the highest coefficient (0.3306) in the PhenoAge linear model, making it the single strongest predictor of biological age. RDW measures variability in red blood cell size, which increases with inflammation, nutritional deficiencies (iron, B12, folate), and chronic disease. Next most impactful are glucose (0.1953) and MCV (0.0268), followed by albumin (-0.0336, protective). Improving RDW through iron, B12, or folate supplementation (if deficient) and reducing glucose through diet can meaningfully reduce PhenoAge.

Yes, and the evidence is compelling. A 2021 randomized trial (Fitzgerald et al., Aging journal) showed a dietary and lifestyle intervention reduced PhenoAge by an average of 3.23 years in 8 weeks. Effective strategies include caloric restriction (reduces glucose and inflammation), time-restricted eating (improves glucose metabolism), aerobic exercise 150+ minutes per week (reduces CRP and RDW), 7-9 hours of quality sleep (reduces inflammatory markers), Mediterranean or whole-food plant-based diet (improves albumin and reduces glucose). Retesting after 3-6 months of consistent changes allows tracking of biological age trends.