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Biological Age Calculator (PhenoAge) — From a Standard Blood Test

The short answer

Enter your age and nine values from a comprehensive metabolic panel, a CBC with differential and an hs-CRP. The calculator returns your phenotypic age — the age at which a typical person's routine blood markers look like yours — using the PhenoAge model published by Levine and colleagues in 2018, with the gap to your calendar age and which markers are pulling the number up or down.

Inputs
Age + 9 markers (CMP, CBC w/ diff, hs-CRP)
Model
PhenoAge (Levine 2018), published coefficients
Units
US by default; SI toggles for albumin, creatinine, glucose, CRP
Cost
Free
From the metabolic panel (CMP) · Albumin range
Creatinine range
Fasting if you have it · Glucose range
High-sensitivity CRP; standard CRP in mg/dL also works · hs-CRP range
The percentage from the CBC differential, not the absolute count · Lymphocytes range
RDW-CV (%), not RDW-SD (fL) · RDW range
Alkaline Phosphatase range
K/µL = ×10³/µL = ×10⁹/L · White Blood Cell Count range

Enter your values to calculate.

xb = −19.9067 − 0.0336·albumin[g/L] + 0.0095·creatinine[µmol/L] + 0.1953·glucose[mmol/L] + 0.0954·ln(CRP[mg/dL]) − 0.0120·lymphocyte% + 0.0268·MCV + 0.3306·RDW + 0.0019·ALP + 0.0554·WBC + 0.0804·age; M = 1 − exp(−e^xb·(e^(120·0.0076927) − 1)/0.0076927); PhenoAge = 141.50225 + ln(−0.00553·ln(1 − M)) / 0.090165

Educational — a derived index, not a diagnosis. Nothing you enter leaves your browser.

How the Biological age (PhenoAge) is calculated

xb = −19.9067 − 0.0336·albumin[g/L] + 0.0095·creatinine[µmol/L] + 0.1953·glucose[mmol/L] + 0.0954·ln(CRP[mg/dL]) − 0.0120·lymphocyte% + 0.0268·MCV + 0.3306·RDW + 0.0019·ALP + 0.0554·WBC + 0.0804·age; M = 1 − exp(−e^xb·(e^(120·0.0076927) − 1)/0.0076927); PhenoAge = 141.50225 + ln(−0.00553·ln(1 − M)) / 0.090165

Worked example

Your age (years)Albumin (g/dL)Creatinine (mg/dL)Glucose (mg/dL)hs-CRP (mg/L)Lymphocytes (%)MCV (fL)RDW (%)Alkaline phosphatase (U/L)White blood cells (K/µL)Biological age (PhenoAge) (years)
454.50.990130901370637.4

Difference from your age: −7.6 years · Likely range (method and lab variation): 34–40 years · Albumin vs a typical value: −0.7 years

How to read the result

The interpretation cut points for this index are being physician-reviewed and will appear here with their sources. The formula above is the published equation and the sources list the papers that define the cut points.

Limits

PhenoAge was fitted on US survey data (NHANES III, 1988–94) to long-term, age-related health outcomes; it is a research estimate of how your routine markers compare with people of different ages, not a measurement of ageing and not a prediction for you individually. Modern assays shift the absolute number by a few years, acute illness inflates it (CRP, WBC), and it was not validated in people under 20 or with acute conditions. The change between two draws at the same lab is more informative than any single figure. General wellness, not diagnosis.

Sources

  • Levine ME, et al. An epigenetic biomarker of aging for lifespan and healthspan. Aging (Albany NY) 2018;10:573–591 (PhenoAge derivation; Table 1 and Supplementary Table S1 coefficients). doi.org/10.18632/aging.101414
  • Liu Z, et al. A new aging measure captures morbidity and mortality risk across diverse subpopulations from NHANES IV: A cohort study. PLoS Med 2018;15:e1002718. doi.org/10.1371/journal.pmed.1002718
  • Kwon D, Belsky DW. A toolkit for quantification of biological age from blood chemistry and organ function test data: BioAge. GeroScience 2021;43:2795–2808. doi.org/10.1007/s11357-021-00480-5

Frequently asked questions

What is biological age, and how is it different from my real age?

Chronological age is the calendar. Biological age is an estimate of how your body's measurable markers compare with people of different ages — here, nine routine blood results read through a published model. A phenotypic age below your calendar age means your markers look like a younger person's; above means older. It is a wellness estimate from a population model, not a measurement of your cells and not a diagnosis.

Which blood tests do I need for this calculator?

A comprehensive metabolic panel (albumin, creatinine, glucose, alkaline phosphatase), a CBC with differential (white blood cells, lymphocyte percentage, MCV, RDW) and a high-sensitivity CRP. TestWell sells the three for about $80 all-in, and panels such as the Essential Health, Longevity & Anti-Aging and Healthy Aging panels already contain every input.

How accurate is a blood-based biological age?

PhenoAge tracked long-term, age-related health outcomes more closely than chronological age in the US survey it was built on and has been validated in later cohorts, so the direction and the trend are meaningful. The absolute number carries a few years of uncertainty between labs and assay methods, and a recent infection raises CRP and white cells enough to add years temporarily. Read the trend between two draws at the same lab, not one figure.

Is this the same as the biological age test Quest sells?

Quest Health's version is a paid software layer over a Quest panel that uses a different proprietary model. This calculator uses PhenoAge, the open, published model the commercial versions benchmark against, and it works with results from Quest, Labcorp or BioReference. For TestWell customers the same calculation appears on the results page at no extra charge when the panel contains the nine inputs.

How often should I recalculate it?

Every three to six months if you are changing something — diet, exercise, sleep, a medication — and once a year otherwise. Use the same lab each time and draw when you are well; the model's inputs move with acute illness.

Can I lower my biological age?

The number moves when its inputs move: lower hs-CRP and glucose, a healthier RDW and ALP, and a stable albumin are the levers the model weights most, and they respond to the usual things — weight, activity, sleep, alcohol, smoking and treating any underlying condition. Changes show up over months, which is why the retest interval matters.

Which biomarkers does this tool cover?

Which tests give you these numbers?

Physician-authorized, drawn at Quest, Labcorp or BioReference. Results in 1–3 business days for most tests.