Biomarkers
Biological Age Calculator: Levine Phenotypic Age from Bloodwork
Free biological age calculator. Computes Levine phenotypic age from 9 blood markers plus chronological age, per Levine 2018, JAMA Network Open.
Parameters
Phenotypic age
- yr
Chronological
- yr
Delta
-
10-yr mortality risk
- %
Coefficients from Levine et al. 2018. Reported as a scalar; interpret in context of other inputs and clinician judgment. Not a diagnostic tool. This is an editorial estimate based on published research, not a medical test result. Out-of-range values warrant clinical follow-up, not self-treatment.
Editorial reference
Optimal vs lab-reference ranges
These are editorial reference points, not clinical targets. Discuss any out-of-range value with a clinician. The "optimal" band is what the longevity literature associates with the lowest all-cause mortality, not what your lab will tell you to chase.
| Marker | Unit | Lab reference | Longevity-optimal | Editorial note |
|---|---|---|---|---|
| hs-CRP | mg/L | less than 3 | less than 0.5 | Acute inflammation distorts a single reading. Repeat after 6 weeks if elevated. |
| HbA1c | % | less than 5.7 | 4.8 to 5.2 | Reflects 2 to 3 month glycaemia. Anaemia and haemoglobin variants can bias the reading. |
| Lp(a) | mg/dL | less than 50, or less than 125 nmol/L | less than 30 | Largely genetic. Measure once in adulthood; repeat only on major intervention. |
| Fasting insulin | uIU/mL | 2 to 24 | less than 5 | Lab "normal" runs much wider than the longevity-optimal band. Pair with fasting glucose for HOMA-IR. |
| Albumin | g/dL | 3.5 to 5.0 | 4.3 to 5.0 | Low-normal albumin tracks all-cause mortality even within the lab reference range. |
| DHEA-S | ug/dL | 80 to 560 (adult) | age and sex percentile | No single optimal number. Target the 75th percentile for your age and sex; absolute cutoffs are misleading. |
| Telomere length | kb | lab-specific | measurement is brittle | Inter-lab variability is large; intra-individual variation between draws is also large. Treat trends with skepticism, not single readings. |
-
hs-CRP
mg/L- Lab
- Optimal
- less than 3
- less than 0.5
Acute inflammation distorts a single reading. Repeat after 6 weeks if elevated.
-
HbA1c
%- Lab
- Optimal
- less than 5.7
- 4.8 to 5.2
Reflects 2 to 3 month glycaemia. Anaemia and haemoglobin variants can bias the reading.
-
Lp(a)
mg/dL- Lab
- Optimal
- less than 50, or less than 125 nmol/L
- less than 30
Largely genetic. Measure once in adulthood; repeat only on major intervention.
-
Fasting insulin
uIU/mL- Lab
- Optimal
- 2 to 24
- less than 5
Lab "normal" runs much wider than the longevity-optimal band. Pair with fasting glucose for HOMA-IR.
-
Albumin
g/dL- Lab
- Optimal
- 3.5 to 5.0
- 4.3 to 5.0
Low-normal albumin tracks all-cause mortality even within the lab reference range.
-
DHEA-S
ug/dL- Lab
- Optimal
- 80 to 560 (adult)
- age and sex percentile
No single optimal number. Target the 75th percentile for your age and sex; absolute cutoffs are misleading.
-
Telomere length
kb- Lab
- Optimal
- lab-specific
- measurement is brittle
Inter-lab variability is large; intra-individual variation between draws is also large. Treat trends with skepticism, not single readings.
Optimal bands derive from observational cohorts (Framingham, ARIC, NHANES) and longevity-clinic consensus, not from regulatory cutoffs. They reflect where mortality curves bottom out, which is a different question from what triggers a clinical diagnosis. A lab "normal" can mask a 10 to 20 year horizon risk; a lab "abnormal" can be benign in context.