Phase 6 · Biometric & Longevity
Biological Age Calculator (PhenoAge)
Your blood panel knows how old you really are. Enter nine standard biomarkers and Levine's PhenoAge algorithm estimates your biological age — and what's driving it.
Educational estimate, not a diagnosis. PhenoAge is a research metric, not medical advice. Lab values vary by assay and a single panel is only a snapshot. Always review real results and health decisions with a licensed physician.
How do you calculate phenotypic age (PhenoAge)?
PhenoAge combines nine blood biomarkers — albumin, creatinine, glucose, C-reactive protein, lymphocyte percentage, mean cell volume, red cell distribution width, alkaline phosphatase and white blood cell count — with your chronological age into a mortality-risk score, which is then expressed as an age in years. A PhenoAge below your real age means your biomarkers look younger than your years.
- The three steps are: xb = −19.907 + Σ(coefficient × marker) + 0.0804·age; a mortality score M = 1 − exp(−exb(e0.0076927·120 − 1) ÷ 0.0076927); then PhenoAge = 141.50225 + ln(−0.00553·ln(1 − M)) ÷ 0.090165.
- Unit mismatch is the usual reason a hand calculation fails. Levine’s coefficients expect SI units, so US results need converting: albumin g/dL ×10, creatinine mg/dL ×88.4, glucose mg/dL ÷18, and CRP mg/L ÷10 before taking the natural log. The full coefficient and unit table is below.
- The markers are not equally weighted. RDW carries by far the most weight per unit — one percentage point moves the result about 3.7 years on this page’s defaults, more than any other single marker.
- Developed by Dr. Morgan Levine and colleagues (Levine et al., Aging, 2018) and validated against mortality in NHANES data. The figure that matters is the gap between PhenoAge and chronological age, and the trend across repeat panels rather than any one result.
Under the hood
The algorithm, fully cited
We convert US units to the algorithm's clinical units, compute a linear predictor, a 10-year mortality score, then express it as an age:
xb = −19.907 − 0.0336·albumin + 0.0095·creatinine + 0.1953·glucose + 0.0954·ln(CRP) − 0.0120·lymph% + 0.0268·MCV + 0.3306·RDW + 0.00188·ALP + 0.0554·WBC + 0.0804·age
Mortality score M = 1 − exp( −exb · (e0.0077·120 − 1) ÷ 0.0077 )
PhenoAge = 141.50 + ln(−0.00553 · ln(1 − M)) ÷ 0.090165
The single most common way to get a wrong answer by hand is a unit mismatch: Levine's coefficients expect clinical (SI) units, while US labs report several of these markers differently. Every coefficient, the unit it expects, and the conversion this page applies:
| Biomarker | Coefficient | Unit the formula expects | Typical US lab unit → conversion | Effect on PhenoAge |
|---|---|---|---|---|
| Albumin | −0.0336 | g/L | g/dL → ×10 | Higher is younger |
| Creatinine | +0.0095 | µmol/L | mg/dL → ×88.4 | Higher is older |
| Glucose | +0.1953 | mmol/L | mg/dL → ÷18 | Higher is older |
| CRP (natural log) | +0.0954 | mg/dL, then ln | mg/L → ÷10, then ln | Higher is older |
| Lymphocyte % | −0.0120 | % | % — no conversion | Higher is younger |
| Mean cell volume (MCV) | +0.0268 | fL | fL — no conversion | Higher is older |
| Red cell distribution width (RDW) | +0.3306 | % | % — no conversion | Higher is older |
| Alkaline phosphatase (ALP) | +0.00188 | U/L | U/L — no conversion | Higher is older |
| White blood cell count (WBC) | +0.0554 | 103 cells/µL | K/µL — no conversion | Higher is older |
| Chronological age | +0.0804 | years | years — no conversion | Higher is older |
| Intercept | −19.907 | — | — | — |
The coefficients are not equally powerful, because each is scaled to its own unit. Holding the defaults above fixed and moving one marker at a time, RDW dominates — a single percentage point is worth more than a 20 U/L swing in ALP by almost nine to one:
RDW +1% → +3.67 yr · albumin −0.5 g/dL → +1.86 yr · glucose +10 mg/dL → +1.20 yr · creatinine +0.1 mg/dL → +0.93 yr · MCV +3 fL → +0.89 yr · CRP +1 mg/L → +0.73 yr · lymphocyte −5% → +0.67 yr · WBC +1 K/µL → +0.61 yr · ALP +20 U/L → +0.42 yr
- Source: Levine ME, Lu AT, Quach A, et al. "An epigenetic biomarker of aging for lifespan and healthspan." Aging (Albany NY). 2018;10(4):573–591. The PhenoAge biomarker model originates in Levine, J Gerontol A. 2013.
- Precision note: the formulas above are shown rounded for readability. This page computes with the unrounded published constants — 141.50225, 0.090165, −0.00553 and γ = 0.0076927 — so results match the paper rather than the rounded display.
- What it means: a PhenoAge below your chronological age suggests biomarkers typical of a younger person; above it suggests accelerated aging. The trend over repeat panels matters more than any single number.
- Worked example: the default panel on this page — age 45, albumin 4.7 g/dL, creatinine 0.9 mg/dL, glucose 90 mg/dL, CRP 1 mg/L, lymphocytes 32%, MCV 90 fL, RDW 13%, ALP 65 U/L, WBC 6 K/µL — gives xb = −9.575, a mortality score of 0.0136, and a PhenoAge of 36.3 years: about 8.7 years younger than chronological age.
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Answers
Frequently asked questions
What is biological or phenotypic age?
Chronological age is how many years you've lived; biological age estimates how old your body appears to function. Two 45-year-olds can have very different biological ages depending on inflammation, metabolic health and organ function. Phenotypic age (PhenoAge) is a specific, validated estimate of biological age built from routine blood markers.
How is PhenoAge calculated?
PhenoAge, developed by Dr. Morgan Levine and colleagues, combines nine blood biomarkers (albumin, creatinine, glucose, C-reactive protein, lymphocyte %, mean cell volume, red cell distribution width, alkaline phosphatase and white blood cell count) plus your chronological age into a mortality-risk score, which is then expressed as an age. It has been shown to predict mortality and healthspan better than chronological age alone.
How do I calculate my phenotypic age?
Get a standard blood panel — a complete blood count (CBC) plus a metabolic panel and a CRP test cover all nine markers: albumin, creatinine, glucose, C-reactive protein, lymphocyte %, mean cell volume, red cell distribution width, alkaline phosphatase and white blood cell count. Enter those nine values plus your chronological age above, and the PhenoAge formula converts them into a mortality-risk score expressed as an age. This calculator runs Levine's published equation instantly, so you do not have to do the math by hand.
What does it mean if my phenotypic age is higher than my chronological age?
It means your biomarkers look "older" than your years — typically driven by elevated inflammation (CRP), high glucose, or other markers trending the wrong way — and is associated with higher health risk. A phenotypic age below your real age suggests your body is aging more slowly. The number to watch is the gap (PhenoAge minus your actual age): a negative gap is good, and because the underlying markers are modifiable, you can work to shrink a positive gap over time.
Can I actually lower my biological age?
The biomarkers behind PhenoAge respond to lifestyle: inflammation (CRP) falls with better diet, sleep, exercise and reduced visceral fat; glucose improves with weight loss and activity; RDW and others reflect nutrition. Because the score is built from these modifiable markers, improving them can genuinely lower your calculated PhenoAge over time. It is not fixed.
What blood tests do I need for a PhenoAge calculation?
There is no special "PhenoAge test" — all nine markers come from three routine panels your doctor can order together. A complete blood count (CBC) with differential supplies lymphocyte percentage, mean cell volume, red cell distribution width and white blood cell count. A comprehensive metabolic panel (CMP) supplies albumin, creatinine, glucose and alkaline phosphatase. The ninth, C-reactive protein, is usually ordered separately — ask for standard CRP rather than high-sensitivity (hs-CRP) if you can, though either works since the formula takes its natural log. Fast beforehand, because the glucose reading assumes a fasting sample.
Why does my hand calculation not match?
Almost always units. Levine’s coefficients expect clinical SI units, while US labs report several markers differently: albumin must be multiplied by 10 (g/dL to g/L), creatinine by 88.4 (mg/dL to µmol/L), glucose divided by 18 (mg/dL to mmol/L), and CRP divided by 10 (mg/L to mg/dL) before taking its natural log. Lymphocyte %, MCV, RDW, ALP and WBC need no conversion. The other common cause is rounding the published constants — this page computes with 141.50225, 0.090165, −0.00553 and γ = 0.0076927, not the shortened versions often quoted.
Is this a medical diagnosis?
No. This is an educational estimate of a research metric, not a diagnosis or medical advice. Lab values vary by assay and timing, and a single panel is a snapshot. Discuss your actual results, trends, and any concerns with a qualified physician — never make health decisions from a calculator alone.