PhenoAge Biological Age Calculator (Levine)
A research estimate using nine biomarkers and age. The result does not predict individual life expectancy.
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Calculation
Result
- Phenotypic age (PhenoAge)
- 31.7 years
- Difference from chronological age
- -8.3 years
The age at which your biomarker profile is typical in the NHANES population
PhenoAge minus age. An arithmetic difference, not a measured rate of aging.
Levine 2018. CRP must be measured and strictly positive. A result below the detection limit cannot be replaced with zero. Reference ranges are population benchmarks from the cited sources. Laboratories use their own ranges, and interpretation depends on clinical context: discuss the result with your physician.
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How it is calculated
The Levine 2018 model combines nine biomarkers and chronological age. Coefficients were trained on NHANES; a Gompertz transformation expresses the profile as an age equivalent of population risk. No individual mortality forecast is shown. The difference from chronological age is simple subtraction, not the statistical PhenoAgeAccel residual or a rate of aging.
Formula
xb = −19.907 − 0.0336·Albumin(g/L) + 0.0095·Creatinine(µmol/L) + 0.1953·Glucose(mmol/L) + 0.0954·ln(CRP, mg/dL) − 0.0120·Lymphocytes(%) + 0.0268·MCV(fL) + 0.3306·RDW(%) + 0.00188·ALP(U/L) + 0.0554·WBC(10⁹/L) + 0.0804·Age 120-month risk = 1 − exp(−e^xb · (e^(120·0.0076927) − 1) / 0.0076927) PhenoAge = 141.50225 + ln(−0.00553 · ln(1 − Risk)) / 0.09165
Limits of the method
Research tool for ages 20–84. Acute illness changes biomarkers and the result. The number is not a diagnosis, lifespan or proof of rejuvenation. CRP below the detection limit requires a quantitative result rather than substituting zero.
Sources of the method
This calculation is for reference only and is not medical advice, a diagnosis or a prescription. If you have a medical condition, are pregnant, take medication or have any doubts, discuss the result with a physician or a qualified nutrition professional.
How to calculate PhenoAge
Get a CBC with differential and a chemistry panel
Needed: albumin, creatinine, fasting glucose, CRP (preferably high-sensitivity), alkaline phosphatase — from chemistry; white cells, lymphocyte %, MCV, RDW — from the blood count.
Enter values in SI units
Albumin in g/L (not g/dL), creatinine in µmol/L, glucose in mmol/L, CRP in mg/L. If your report uses other units, use the unit converter.
Track the trend, not a single number
Interpret the laboratory results with a clinician. A change in the number does not prove rejuvenation or intervention effectiveness.
PhenoAge worked examples
Age 40: albumin 45, creatinine 80, glucose 5.0, CRP 0.5
Lymphocytes 30%, MCV 90, RDW 12.5, ALP 60, WBC 5.5 → 31.7 years.
Age 55: albumin 42, creatinine 95, glucose 6.1, CRP 3.5
Lymphocytes 24%, MCV 93, RDW 14.2, ALP 85, WBC 7.2 → 61.2 years.
Age 48: albumin 38, creatinine 105, glucose 7.4, CRP 9.0
Lymphocytes 18%, MCV 97, RDW 15.8, ALP 110, WBC 9.5 → 71.0 years.
What PhenoAge actually measures
The nine markers reflect key aging processes: chronic inflammation (CRP, white cells, lymphocytes), glucose metabolism, kidney and liver function (creatinine, albumin, ALP) and the quality of blood formation (MCV, RDW). RDW is especially informative — the spread of red cell sizes, which widens with inflammation, deficiencies and oxidative stress — and proved one of the strongest mortality predictors at all ages. PhenoAge correlates with the DNAm PhenoAge epigenetic clock and predicts not only mortality but multimorbidity, physical function and cognitive scores.
Can this number be a treatment target?
The calculator does not prescribe interventions to lower PhenoAge. Population associations do not establish a benefit from changing a single biomarker or the score itself.
PhenoAge biomarkers and their direction
| Marker | What it reflects | Coefficient sign |
|---|---|---|
| Albumin | Protein status, liver function, inflammation | Negative |
| Creatinine | Kidney function (and muscle mass) | Positive |
| Glucose | Glucose metabolism, insulin resistance | Positive |
| CRP | Systemic inflammation | Positive |
| Lymphocytes, % | Immune aging | Negative |
| MCV | Red cell size, B12/folate status, alcohol | Positive |
| RDW | Red cell heterogeneity: inflammation, deficiencies | Positive |
| Alkaline phosphatase | Liver, biliary tract, bone | Positive |
| White blood cells | Inflammation, smoking, stress | Positive |
A coefficient sign describes the model, not a treatment target. Do not change a biomarker solely to lower this number.
Frequently asked questions
How accurate is PhenoAge?
The model has been studied in populations. This calculator does not provide an individual confidence interval or promise accuracy within a few years.
How does PhenoAge differ from epigenetic clocks?
This is a clinical model based on blood biomarkers. DNAm PhenoAge is a separate DNA methylation model; the results are not interchangeable.
Which tests are needed and what do they cost?
A complete blood count with differential and red cell indices plus chemistry: albumin, creatinine, glucose, CRP, alkaline phosphatase. This is a standard check-up included in most screening programs.
Can biological age be lowered?
Changing biomarkers changes the calculation. A lower number alone does not demonstrate slower aging or longer life.
Why did PhenoAge jump 10 years after a cold?
Acute illness changes CRP and other markers and may substantially alter the number. Such a result should not be interpreted as changed aging. Discuss appropriate testing timing with a clinician.
Is PhenoAge suitable for athletes?
Muscle mass and recent exercise can affect biomarkers. The model has no athlete adjustment and does not measure fitness.
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Break biological age down into its components:
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What next
Formula breakdowns, biomarker reference ranges and nutrition articles with cited sources are in the NutriFit knowledge base.
Go to the knowledge base