Free PhenoAge calculator

PhenoAge turns nine numbers from a routine blood test, plus your age, into a biological age. Morgan Levine and colleagues built it in 2018 from 9,926 American adults [1]. In 11,432 more, followed for up to 12 years, each year it read above real age went with a 9% higher risk of death [2].

It is free if you already have the blood work. Our buyer's guide to biological age tests compares it with DNA kits that cost up to $499.

What you need

Eight of the nine markers are on two tests doctors order all the time. CRP usually has to be added.

  • Metabolic panel (fasting): albumin, creatinine, glucose, alkaline phosphatase (ALP).
  • Full blood count with differential: lymphocytes (%), mean cell volume (MCV), red cell distribution width (RDW), white blood cells.
  • CRP, a marker of inflammation. High-sensitivity CRP (hs-CRP) works too.

Pick the unit printed on your report for each line. If your report says CRP is below a limit, such as "<0.3", type it that way.

Your numbers stay in your browser. Nothing you type is sent to us or saved. We only count that the calculator was used.

How to read your result

It reads young in healthy people. Doctor Hillary Lin's PhenoAge was 20.4 at a real age of 35.5 [3]. The formula compares you with American adults surveyed from 1988 to 1994. As Lin put it, "a healthy, optimized person will always score well against a population baseline that includes widespread metabolic dysfunction." A young score is good news, not a trophy.

A cold, an infection or a hard workout the day before can raise CRP and white cells, and with them your score. Test when you are well, fasting, at the same time of day.

One number is a snapshot. Compare tests from the same lab, and judge a trend over three results, not one.

A high score is not a disease, and a low one is not a clean bill of health. Take any result your lab flagged to your doctor, not to a calculator.

How it works

This is Levine's clinical PhenoAge formula [1], the one most free calculators use. It weighs the nine markers and your age, estimates the risk of death over 10 years, then turns that risk into the age with the same risk in the original survey.

The formula wants albumin in g/L, creatinine in µmol/L, glucose in mmol/L and CRP in mg/dL, and we convert the rest. CRP is the one to watch: most labs print it in mg/L, which is ten times the mg/dL number. Picking the wrong one moves the result by about 2.4 years.

"What moved your number" swaps each marker, one at a time, for the middle of the usual lab range: albumin 4.25 g/dL, creatinine 0.9 mg/dL, glucose 84.5 mg/dL, CRP 1 mg/L, lymphocytes 30%, MCV 90 fL, RDW 13%, ALP 95.5 U/L, white cells 7.75 ×10³/µL. It shows how many years each swap changes. These are not targets.

Sources

  1. Levine ME, Lu AT, Quach A, et al. An epigenetic biomarker of aging for lifespan and healthspan. Aging, 2018. Clinical PhenoAge built on 9,926 adults in NHANES III, observational. doi:10.18632/aging.101414
  2. Liu Z, Kuo PL, Horvath S, Crimmins E, Ferrucci L, Levine M. A new aging measure captures morbidity and mortality risk across diverse subpopulations from NHANES IV: a cohort study. PLOS Medicine, 2018. 11,432 adults aged 20 to 84 plus 185 aged 85 and over, observational, up to 12.6 years. Funded by the US National Institute on Aging. doi:10.1371/journal.pmed.1002718
  3. Lin H. Your biological age test might be lying to you. Newsletter, March 23, 2026. newsletter.hillarylinmd.com