Free biological age calculator
How old is your body?
Enter nine routine blood results to get your PhenoAge, or answer eight heart-health questions if you have no blood test.
A biological age calculator estimates how old your body seems from measures of its health. This one uses PhenoAge, a published formula that turns nine routine blood results and your age into an age in years. In US data, each extra year of PhenoAge went with about 9% higher risk of death at the same real age.[1]
Biological age at a glance
- Method: PhenoAge by Levine and colleagues (2018), trained on US national health survey data and tested on a separate national sample.[1][2]
- Tests needed: a metabolic panel, a blood count with differential and a CRP test. No DNA kit needed.[1]
- Risk link: each 1-year rise in PhenoAge went with about 9% higher all-cause mortality risk.[1]
- No blood test? High heart-health scores on the AHA Life’s Essential 8 went with a biological age about 6 years younger than low scores.[4]
- Can it change? In a 2-year trial, moderate calorie restriction slowed a DNA-based pace of aging by 2 to 3%.[7]
How to use the biological age calculator
- Choose your path. Pick “I have blood test results” for PhenoAge, or “No blood test” for a heart-health score.
- Pick your units. US reports use g/dL and mg/dL. SI reports use g/L, µmol/L and mmol/L. Set the CRP unit next to the CRP box.
- Enter all nine results from one blood test, and your age on the day of the test. Say whether the glucose was fasting.
- Read the breakdown. “What changed your result” shows how many years each test adds or removes.
- Save it. Save each new test to track your biological age over time, or copy a link to the result.
What is biological age?
Biological age is how old your body seems, judged by measures of health rather than by your birth date. PhenoAge defines it as the age at which an average US adult would carry the same mortality risk as your results suggest.[2]
Two people born the same year can age at different rates. Researchers found that PhenoAge rose with the number of diseases a person had, and still predicted death among people who reported no disease and had a normal BMI.[2] That is why biological age is used in research as a summary of how the body is wearing, beyond the calendar.
How this biological age calculator works
The calculator uses the PhenoAge formula. Levine and colleagues selected nine blood tests and age out of 42 candidate measures by how well they predicted death in US national survey data, then turned the combined risk into years.[1]
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 (10³/µL) + 0.0804 × age
mortality score M = 1 − exp(−1.51714 × exb / 0.0076927)
PhenoAge = 141.50 + ln(−0.0055305 × ln(1 − M)) / 0.090165
The coefficients are from the original paper, at the full precision used in the BioAge research toolkit.[1][3] Units matter. Albumin must be in g/L, creatinine in µmol/L, glucose in mmol/L and CRP in mg/dL before the natural log. A common error online is entering CRP in mg/L without dividing by 10, which adds about 2.4 years. The calculator converts everything for you.
The two steps simplify to a straight line. PhenoAge equals about 142.5 plus xb divided by 0.090165, so each test adds or removes a fixed number of years. That is how the calculator shows an exact breakdown. This last point is our own algebra on the published formula.
Example: a 45-year-old with albumin 4.2 g/dL, creatinine 0.9 mg/dL, fasting glucose 92 mg/dL, CRP 1.5 mg/L, lymphocytes 30%, MCV 90 fL, RDW 13.2%, ALP 70 U/L and a white cell count of 6.0 has a PhenoAge of 39.8, about 5.2 years younger than real age.
Which blood tests do you need for a biological age test?
You need three common tests: a comprehensive metabolic panel, a complete blood count with differential and a CRP or high-sensitivity CRP test. Glucose should be fasting.[1]
| Blood test | Where to find it | US unit | SI unit | Higher value |
|---|---|---|---|---|
| Albumin | Metabolic panel (CMP) | g/dL | g/L (×10) | Younger |
| Creatinine | Metabolic panel (CMP) | mg/dL | µmol/L (×88.4) | Older |
| Glucose, fasting | Metabolic panel (CMP) | mg/dL | mmol/L (÷18) | Older |
| Alkaline phosphatase | Metabolic panel (CMP) | U/L | U/L | Older |
| C-reactive protein | CRP or hs-CRP test | mg/L or mg/dL | mg/L | Older |
| White blood cell count | Blood count (CBC) | ×10³/µL | ×10⁹/L (same number) | Older |
| Lymphocyte percent | CBC with differential | % | % | Younger |
| Mean cell volume (MCV) | Blood count (CBC) | fL | fL | Older |
| Red cell distribution width (RDW) | Blood count (CBC) | % | % | Older |
Many annual checkups include the first two. CRP is often a separate order. The hs-CRP version measures low levels more precisely and is the one used for heart risk.[8]
Which result moves biological age the most?
RDW and blood sugar carry the most weight per typical change. RDW measures how much red blood cells vary in size. A 1-point rise adds about 3.7 years, and a 1 mmol/L (18 mg/dL) rise in fasting glucose adds about 2.2 years.[1]
| Change in one result, all else equal | Change in PhenoAge |
|---|---|
| RDW 1 point higher (for example 13% to 14%) | +3.7 years |
| Creatinine 0.3 mg/dL higher (27 µmol/L) | +2.8 years |
| Fasting glucose 18 mg/dL higher (1 mmol/L) | +2.2 years |
| Albumin 0.5 g/dL lower (5 g/L) | +1.9 years |
| MCV 5 fL higher | +1.5 years |
| Lymphocytes 10 points lower (for example 30% to 20%) | +1.3 years |
| White cell count 2 ×10³/µL higher | +1.2 years |
| CRP three times higher (for example 1 to 3 mg/L) | +1.2 years |
| Alkaline phosphatase 30 U/L higher | +0.6 years |
How to read your biological age result
Compare PhenoAge with your real age. A lower number means your blood results look like those of a younger average adult. In US validation data, each extra year of PhenoAge went with about 9% higher risk of death at the same real age.[1]
Results a few years under your real age are common when all tests are in range, because the formula compares you with the average US adult, not with the healthiest. The table shows what mid-range results give at each age.
| Real age | PhenoAge with mid-range results | Difference |
|---|---|---|
| 30 | 24.3 | −5.7 years |
| 40 | 33.2 | −6.8 years |
| 50 | 42.2 | −7.8 years |
| 60 | 51.1 | −8.9 years |
| 70 | 60.0 | −10.0 years |
| 80 | 68.9 | −11.1 years |
A single result can be thrown off. CRP rises with infection and inflammation, so a cold or an injury can add years for a few weeks.[8] A non-fasting glucose reads higher. To compare over time, use the same lab, test fasting and while well, and save each result in the calculator.
How to calculate biological age without a blood test
No formula can give a trustworthy biological age from lifestyle answers alone. The “No blood test” option gives your American Heart Association Life’s Essential 8 score instead, which has a measured link to PhenoAge.[5][4]
In 6,593 US adults from the 2015 to 2018 national survey, people with high scores averaged a real age of 41 and a PhenoAge of 36. People with low scores averaged a real age of 53 and a PhenoAge of 57. After accounting for social and economic factors, the highest scores went with a biological age about 6 years younger than the lowest. This was a preliminary conference study measured at one point in time.[4]
| Measure | Full 100 points | Zero points |
|---|---|---|
| Diet (16-item Mediterranean screener) | 15 or 16 habits | 0 to 3 habits |
| Physical activity | 150+ minutes a week | None |
| Nicotine | Never smoked | Smokes now |
| Sleep | 7 to under 9 hours a night | Under 4 hours |
| Body mass index | Under 25 | 40 or higher |
| Non-HDL cholesterol | Under 130 mg/dL | 220 mg/dL or higher |
| Blood sugar | Fasting glucose under 100 mg/dL or HbA1c under 5.7% | Diabetes with HbA1c 10% or higher |
| Blood pressure | Under 120/80 mmHg | 160/100 mmHg or higher |
The diet measure uses the Mediterranean Eating Pattern for Americans, a 16-item screener. Each habit, such as eating beans 3 or more times a week, scores one point.[6] It also gives a point for light drinking, as Mediterranean diets often include a little wine. That is not a reason to start drinking.
Aging may not be steady, either. A study of 2,925 blood proteins in 4,263 people aged 18 to 95 found that protein levels shifted in three waves, peaking around ages 34, 60 and 78. This is early research and is not part of PhenoAge.[10]
Can you lower your biological age?
Some evidence says yes, slowly. In the CALERIE trial, healthy adults who cut calories moderately for 2 years slowed a DNA-based pace-of-aging measure by 2 to 3%. Two other clocks, including DNA-based PhenoAge, did not change.[7]
Several PhenoAge tests respond to everyday health. Fasting glucose and CRP track metabolic health and inflammation, and the Life’s Essential 8 habits go with lower PhenoAge in population data.[4] No supplement has been shown to lower PhenoAge in a trial.
Fitness is one of the strongest single links to a long life found so far. In 122,007 adults who had treadmill tests, the risk of death that went with low fitness was as large as or larger than the risk that went with smoking or diabetes.[11] The VO2 max calculator estimates your fitness.
- Move most days. Aim for 150 minutes a week. Check your aerobic fitness with the VO2 max calculator.
- Eat a Mediterranean-style pattern. Vegetables, leafy greens such as spinach, beans, nuts and olive oil. See the anti-aging diet guide and the healthy diet basics.
- Sleep 7 to 9 hours. Late caffeine cuts sleep. The caffeine calculator shows what is left at bedtime.
- Do not smoke or vape. Nicotine exposure is one of the eight measures.
- Know your numbers. Blood pressure, cholesterol and fasting glucose are in both tools on this page.
The calorie-restriction trial was not a fasting trial. If you are curious about meal timing, the intermittent fasting calculator plans an eating window, but it makes no aging claims. For a traditional angle on daily routine, the free dosha quiz shows which dosha leads for you.
Biological age tests compared: blood, DNA and pace of aging
PhenoAge from routine blood tests is the cheapest validated option. DNA methylation tests, often called epigenetic clocks, read chemical marks on DNA and come in several generations with different goals.[9]
| Test | What it reads | Built to predict | Notes |
|---|---|---|---|
| PhenoAge (this calculator) | Nine routine blood results and age | Death and disease risk | Costs only the blood draw. Moves with illness and fasting. |
| Horvath and Hannum clocks | DNA methylation | Chronological age | First generation. Weak link to health beyond age. |
| DNAm PhenoAge and GrimAge | DNA methylation | Phenotypic age, time to death | Second generation. Stronger link to mortality. |
| DunedinPACE | DNA methylation | Pace of aging per year | A speedometer, not an age. Slowed 2 to 3% in a calorie-restriction trial. |
What this biological age calculator cannot know
PhenoAge was built from US adults aged 20 to 84 to rank mortality risk across a population.[2] It cannot see your genes, fitness, family history or medicines, and it cannot tell a short-term change from a lasting one. Results outside the usual range, such as a very high CRP or glucose, may point to a health problem that needs a doctor rather than a lifestyle fix.
The Life’s Essential 8 score measures heart health, not age. Its link to PhenoAge comes from group averages, so your own biological age may differ.
More free tools for daily health decisions.
Biological age calculator FAQ
What is biological age?
Biological age is an estimate of how old your body seems from measures of its health, rather than from your birth date. PhenoAge expresses it as the age at which an average US adult would carry the same mortality risk as your blood results suggest.
How is biological age calculated?
The calculator uses PhenoAge, published by Levine and colleagues in 2018. It weights nine routine blood results and your age, turns the sum into a 10-year mortality risk, and converts that risk back into years.
Is this biological age calculator accurate?
It uses the exact published PhenoAge coefficients and units, and matches the reference implementation. The result is still an estimate. In US validation data, each extra year of PhenoAge was linked to about 9% higher risk of death, but a single blood test can be off because of illness or lab differences.
What blood tests do I need for a biological age test?
A comprehensive metabolic panel (albumin, creatinine, glucose, alkaline phosphatase), a complete blood count with differential (white cell count, lymphocyte percent, MCV, RDW) and a CRP or hs-CRP test. Use a fasting glucose result.
Can I calculate my biological age without a blood test?
Not reliably. Lifestyle-only calculators use made-up formulas. The no-blood-test tab instead gives your American Heart Association Life’s Essential 8 score. In US adults, people with high scores averaged a PhenoAge about 5 years below their real age, and those with low scores about 4 years above it.
What is a good biological age?
A PhenoAge at or below your real age. A 50-year-old with mid-range values on all nine tests scores about 42, so results a few years under your age are common when every test is in range.
Can you lower your biological age?
Several results in the formula, such as glucose, CRP and albumin, respond to health and habits. In a 2-year trial, moderate calorie restriction slowed a DNA-based pace-of-aging measure by 2 to 3%. No supplement has been shown to lower PhenoAge.
How often should I check my biological age?
When you have new blood work, usually once or twice a year. Compare results from the same lab, taken fasting and while you are well, and save each result in the calculator to see the trend.
Why is my biological age higher than my real age?
Check the "What changed your result" list. Common causes are a recent infection raising CRP, a non-fasting glucose, or a high RDW. Retest when you are well, and discuss any result outside your lab’s range with a doctor.
What is the difference between PhenoAge and a DNA methylation test?
PhenoAge uses routine blood chemistry and costs only the blood draw. DNA methylation tests, also called epigenetic clocks, read chemical marks on DNA. Some, such as GrimAge, predict mortality well, while first-generation clocks mainly predict chronological age.
Is the Levine or Yale biological age calculator the same as this one?
Yes. Searches for the Levine, Yale or blood-test biological age calculator usually mean PhenoAge, the formula this calculator uses.
Do we age in bursts at 34, 60 and 78?
One study suggests so. Researchers measured 2,925 blood proteins in 4,263 people aged 18 to 95 and found that protein levels shifted in three waves, peaking around ages 34, 60 and 78. It is early research, and it does not change how PhenoAge is calculated.
What is the strongest predictor of longevity?
No single measure, but fitness is one of the strongest found so far. In a 2018 study of 122,007 adults who had treadmill tests, the risk of death linked to low fitness was as large as or larger than the risk linked to smoking or diabetes. The VO2 max calculator on this site estimates your fitness.
Does this calculator store my blood results?
The calculator runs in your browser. Results you choose to save stay in this browser only, and you can clear them any time. A copied link carries your values inside the link, so share it only with people you trust.
Sources
- 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 (Table 1 and Supplement 1). doi.org/10.18632/aging.101414
- 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;15(12):e1002718. doi.org/10.1371/journal.pmed.1002718
- Kwon D, Belsky DW. A toolkit for quantification of biological age from blood chemistry and organ function test data: BioAge. GeroScience. 2021;43:2795-2808. pmc.ncbi.nlm.nih.gov/articles/PMC8602613
- American Heart Association news release on the Hosalili, Makarem and colleagues abstract presented at Scientific Sessions 2023 (NHANES 2015-2018), November 6, 2023. eurekalert.org/news-releases/1006513
- Lloyd-Jones DM, Allen NB, Anderson CAM, et al. Life’s Essential 8: updating and enhancing the American Heart Association’s construct of cardiovascular health. Circulation. 2022;146(5):e18-e43. ahajournals.org/doi/10.1161/CIR.0000000000001078
- Cerwinske LA, Rasmussen HE, Lipson S, Volgman AS, Tangney CC. Evaluation of a dietary screener: the Mediterranean Eating Pattern for Americans tool. Journal of Human Nutrition and Dietetics. 2017;30(5):596-603. doi.org/10.1111/jhn.12451
- Waziry R, Ryan CP, Corcoran DL, et al. Effect of long-term caloric restriction on DNA methylation measures of biological aging in healthy adults from the CALERIE trial. Nature Aging. 2023;3:248-257. nature.com/articles/s43587-022-00357-y
- MedlinePlus Medical Encyclopedia. C-reactive protein. US National Library of Medicine. medlineplus.gov/ency/article/003356.htm
- Review: epigenetic clocks and EpiScores as clinical biomarkers, with a comparison of the Horvath, Hannum, PhenoAge, GrimAge and DunedinPACE clocks. Journal of Clinical Medicine. 2025;14(10):3604. mdpi.com/2077-0383/14/10/3604
- Lehallier B, Gate D, Schaum N, et al. Undulating changes in human plasma proteome profiles across the lifespan. Nat Med. 2019;25(12):1843-1850. pubmed.ncbi.nlm.nih.gov/31806903
- Mandsager K, Harb S, Cremer P, et al. (2018). Association of cardiorespiratory fitness with long-term mortality among adults undergoing exercise treadmill testing. JAMA Network Open, 1(6), e183605. pmc.ncbi.nlm.nih.gov/articles/PMC6324439
This calculator gives an estimate for general education, not a diagnosis. PhenoAge was built from US population data to rank mortality risk, and a single blood test can be thrown off by illness, fasting status or lab differences. Talk to a doctor about any result outside your lab’s reference range.
