What is my biological age?
Type your age and nine results from a routine blood test (a metabolic panel, a complete blood count and CRP). The biological age calculator works out your phenotypic age with the Levine 2018 PhenoAge formula and how far it is from your age. It is a research estimate, not a diagnosis.
- Biological age (PhenoAge)
- 37.4
Your biological age (PhenoAge) is 37.4 years.
- Difference from your age (years)
- -7.6
- 10-year mortality score
- 1.5%
Biological age (PhenoAge): 37.4. Your biological age (PhenoAge) is 37.4 years.
This calculator gives general information only. It is not medical advice and does not replace a doctor or other health care provider. Talk with a professional about your results. Terms of use
How to calculate
Estimates your biological age (phenotypic age, PhenoAge) from nine routine blood test results and your age with the Levine 2018 formula, and how far it is from your age in years.
Example with the default inputs (Age (years) 45, Lab units US, Albumin (g/dL) 4.5, Creatinine (mg/dL) 0.9, Glucose (mg/dL) 90, C-reactive protein (mg/L) 1, Lymphocytes (%) 30, Mean cell volume (fL) 90, Red cell distribution width (%) 13, Alkaline phosphatase (U/L) 70, White blood cells (×1000/µL) 6): Your biological age (PhenoAge) is 37.4 years.
Method: xb = −19.907 − 0.0336 × albumin + 0.0095 × creatinine + 0.1953 × glucose + 0.0954 × ln(CRP) − 0.0120 × lymphocyte % + 0.0268 × MCV + 0.3306 × RDW + 0.00188 × ALP + 0.0554 × WBC + 0.0804 × age; M = 1 − exp(−1.51714 × e^xb ÷ 0.0076927); PhenoAge = 141.50225 + ln(−0.00553 × ln(1 − M)) ÷ 0.090165.
- Units in the formula: albumin g/L, creatinine µmol/L, glucose mmol/L, CRP mg/dL (the typed mg/L ÷ 10), lymphocytes %, MCV fL, RDW %, ALP U/L, WBC 1000 cells/µL.
- US units convert as albumin g/dL × 10, creatinine mg/dL × 88.4 (KDIGO), glucose mg/dL ÷ 18.016.
- The formula was trained on US adults (NHANES III) to predict 10-year mortality; it is a research estimate, not a diagnosis.
Worked examples
Each example is checked against the calculator on every build.
- Age (years) 45, Lab units US, Albumin (g/dL) 4.5, Creatinine (mg/dL) 0.9, Glucose (mg/dL) 90, C-reactive protein (mg/L) 1, Lymphocytes (%) 30, Mean cell volume (fL) 90, Red cell distribution width (%) 13, Alkaline phosphatase (U/L) 70, White blood cells (×1000/µL) 6 gives Biological age (PhenoAge) 37.374585, Difference from your age (years) -7.625415, 10-year mortality score 1.50157%.Source: Levine ME and others, An epigenetic biomarker of aging for lifespan and healthspan, Aging 2018;10:573, Table 1 (phenotypic age weights), https://pmc.ncbi.nlm.nih.gov/articles/PMC5940111/; The full PhenoAge formula (intercept −19.907, 1.51714, 0.0076927, 141.50225, 0.00553, 0.090165) as printed in https://pmc.ncbi.nlm.nih.gov/articles/PMC12172999/ (retrieved 2026-10-05)
- Age (years) 60, Lab units SI, Albumin (g/L) 38, Creatinine (µmol/L) 110, Glucose (mmol/L) 6.1, C-reactive protein (mg/L) 5, Lymphocytes (%) 22, Mean cell volume (fL) 95, Red cell distribution width (%) 15, Alkaline phosphatase (U/L) 95, White blood cells (×1000/µL) 8 gives Biological age (PhenoAge) 72.295204, Difference from your age (years) 12.295204, 10-year mortality score 29.712566%.Source: Levine ME and others, An epigenetic biomarker of aging for lifespan and healthspan, Aging 2018;10:573, Table 1 (phenotypic age weights), https://pmc.ncbi.nlm.nih.gov/articles/PMC5940111/; The full PhenoAge formula (intercept −19.907, 1.51714, 0.0076927, 141.50225, 0.00553, 0.090165) as printed in https://pmc.ncbi.nlm.nih.gov/articles/PMC12172999/ (retrieved 2026-10-05)
- Age (years) 30, Lab units US, Albumin (g/dL) 4.8, Creatinine (mg/dL) 0.8, Glucose (mg/dL) 85, C-reactive protein (mg/L) 0.3, Lymphocytes (%) 35, Mean cell volume (fL) 88, Red cell distribution width (%) 12, Alkaline phosphatase (U/L) 60, White blood cells (×1000/µL) 5 gives Biological age (PhenoAge) 14.325278, Difference from your age (years) -15.674722.Source: Levine ME and others, An epigenetic biomarker of aging for lifespan and healthspan, Aging 2018;10:573, Table 1 (phenotypic age weights), https://pmc.ncbi.nlm.nih.gov/articles/PMC5940111/; The full PhenoAge formula (intercept −19.907, 1.51714, 0.0076927, 141.50225, 0.00553, 0.090165) as printed in https://pmc.ncbi.nlm.nih.gov/articles/PMC12172999/ (retrieved 2026-10-05)
How it works
Linear predictor (units below):
xb = −19.907 − 0.0336 × albumin + 0.0095 × creatinine + 0.1953 × glucose + 0.0954 × ln(CRP) − 0.0120 × lymphocyte % + 0.0268 × MCV + 0.3306 × RDW + 0.00188 × ALP + 0.0554 × WBC + 0.0804 × age
Units: albumin g/L, creatinine µmol/L, glucose mmol/L, CRP mg/dL, lymphocytes %, MCV fL, RDW %, ALP U/L, WBC 1000 cells/µL, age years.
- 10-year mortality score M = 1 − exp(−1.51714 × e^xb ÷ 0.0076927), shown in percent.
- Biological age (PhenoAge) = 141.50225 + ln(−0.00553 × ln(1 − M)) ÷ 0.090165.
- Because ln(1 − M) = −1.51714 × e^xb ÷ 0.0076927 exactly, the page computes PhenoAge = 141.50225 + (ln(0.00553 × 1.51714 ÷ 0.0076927) + xb) ÷ 0.090165, the same value without rounding 1 − M.
- Difference = PhenoAge − age.
Unit conversions. CRP is typed in mg/L and divided by 10 for mg/dL. In US units: albumin g/dL × 10 = g/L; creatinine mg/dL × 88.4 = µmol/L; glucose mg/dL ÷ 18.016 = mmol/L.
Rules. Age 18 to 100; albumin 1 to 7 g/dL (10 to 70 g/L); creatinine 0.1 to 15 mg/dL (9 to 1,330 µmol/L); glucose 20 to 600 mg/dL (1.1 to 33.3 mmol/L); CRP 0.01 to 300 mg/L; lymphocytes 1% to 90%; MCV 50 to 130 fL; RDW 8% to 30%; ALP 10 to 1,000 U/L; WBC 0.5 to 100. A PhenoAge below 0 gives no answer.
Output format. PhenoAge and the difference show 1 decimal; the mortality score shows 1 decimal of a percent. Everything except the logarithm and the exponential is exact arithmetic on the typed decimals.
Assumptions
- Adults; the model comes from US adults in NHANES III and was checked in NHANES IV.
- Results from one blood draw, ideally fasting, with no acute illness.
Worked examples by hand
Checked with Python 3 (math.log, math.exp) on the formula above.
Age 45, US units: albumin 4.5 g/dL, creatinine 0.9 mg/dL, glucose 90 mg/dL, CRP 1 mg/L, lymphocytes 30%, MCV 90, RDW 13, ALP 70, WBC 6. Albumin 45 g/L, creatinine 79.56 µmol/L, glucose 4.9956 mmol/L, CRP 0.1 mg/dL. xb = −9.4754. M = 1.5%. PhenoAge = 37.37 (shown 37.4), difference −7.6 years.
Age 60, SI units: albumin 38 g/L, creatinine 110 µmol/L, glucose 6.1 mmol/L, CRP 5 mg/L, lymphocytes 22%, MCV 95, RDW 15, ALP 95, WBC 8. xb = −6.3268. M = 29.7%. PhenoAge = 72.30, difference +12.3 years.
Age 30, US units: albumin 4.8, creatinine 0.8, glucose 85, CRP 0.3, lymphocytes 35%, MCV 88, RDW 12, ALP 60, WBC 5. xb = −11.5537. PhenoAge = 14.33 (shown 14.3), difference −15.7 years.
Other questions people ask
What is biological age?
Biological age is an estimate of how old your body seems from measurements, rather than from your birthday. Two people of 50 can have different biological ages if one has blood results more typical of an older person.
What is PhenoAge?
Phenotypic age (PhenoAge) is a biological age built by Morgan Levine and colleagues in 2018 from nine blood markers and age. It was trained to predict the 10-year risk of death in US adults and is expressed as the age with that average risk.
Which blood tests do I need?
Albumin, creatinine, glucose, C-reactive protein (CRP), lymphocyte percent, mean cell volume (MCV), red cell distribution width (RDW), alkaline phosphatase and white blood cell count. They come from a comprehensive metabolic panel, a complete blood count with differential, and a CRP test.
What does a negative difference mean?
A negative difference means your PhenoAge is lower than your age: your results look like those of a younger average person. A positive difference means they look older. The number moves with each test, so one result is a snapshot.
Can I lower my biological age?
PhenoAge moves with its markers. Inflammation (CRP), blood sugar and RDW weigh a lot, and they respond to exercise, weight, sleep, not smoking and treating illness. Talk with your doctor about any abnormal result rather than chasing the score.
How accurate is a biological age calculator?
PhenoAge predicted death and disease better than age alone in the study population, but it is an average model. An infection or a short-term illness can raise CRP or white cells and add years for a while. Use it to follow trends, not to judge your health.