Blood age calculator: how old does your blood say you are?
Type in nine results from a routine blood test and get your blood age from a published formula. Free, and nothing you type leaves your browser. It is an estimate, not a diagnosis.
Enter your numbers
All nine from the same test, taken fasting and when you were well. The unit is printed next to each result on your report.
Don't know your numbers?
In Bali or Jakarta, a nurse comes to you. Tell us you want the nine blood-age results and we'll point you to the package that covers them, alongside your hormones.
How the blood age is worked out
In 2018 a research group led by Morgan Levine looked at 42 routine blood measures in 9,926 US adults who had been followed for 23 years. Nine of those measures, together with age, said the most about how long people went on to live. The researchers turned that into a single figure in years, which they called Phenotypic Age, and then checked it on a further 6,209 adults.
This calculator runs that formula on your numbers. If your nine results look like those of a typical 35-year-old in the study, your blood age is 35, whatever your birthday says.
It is a statement about groups of people, not a prediction about you. A single test is a snapshot. The useful part is the direction it moves when you test again.
The nine results, and where to find them
| Result | On your report under | Units |
|---|---|---|
| Albumin | Liver panel | g/L or g/dL |
| Creatinine | Kidney panel | µmol/L or mg/dL |
| Fasting glucose | Fasting sample only | mmol/L or mg/dL |
| hs-CRP | Inflammation | mg/L or mg/dL |
| Lymphocytes | Full blood count | % or ×10⁹/L |
| MCV (red cell size) | Full blood count | fL |
| RDW (red cell size spread) | Full blood count | % |
| ALP (alkaline phosphatase) | Liver panel | U/L |
| White blood cells | Full blood count | ×10⁹/L |
White blood cells in ×10⁹/L is the same number as ×10³/µL. If your report gives lymphocytes as a count rather than a percentage, choose ×10⁹/L and the calculator works out the share.
What is blood age?+
Blood age is an estimate of how old your body looks from a routine blood test, compared with your actual age. This calculator uses a published formula, often called Phenotypic Age, that combines nine common blood results with your age. It is an estimate, not a diagnosis, and it says nothing about any one disease.
Which formula does this calculator use?+
The Phenotypic Age formula from Levine and colleagues, published in the journal Aging in 2018. It was built from 9,926 US adults, women and men, followed for 23 years, and then checked on a further 6,209 adults. We use the weights as its authors published them in their own reference code.
Which blood results do I need?+
Nine, all from the same test: albumin, creatinine, fasting glucose, hs-CRP, lymphocytes, MCV, RDW, ALP and white blood cells. Most come with a full blood count plus a liver and kidney panel. Fasting glucose and hs-CRP are sometimes ordered separately. A hormone panel on its own does not include them.
Is anything I type sent or stored?+
No. The sum is done in your browser. The numbers you type are not sent to Her Form or anyone else, and they are gone when you close the page.
Does my cycle, pregnancy or the pill change the result?+
They can. Inflammation and iron markers shift across the cycle, and pregnancy changes several of the nine results a great deal, so the formula should not be used during pregnancy. The study did not separate women by cycle phase or contraception, so treat the number as a rough guide and compare tests taken at the same point in your cycle.
My blood age is older than my actual age. What now?+
Treat it as a starting point. One test is a snapshot, and results move with sleep, training, illness and what you ate. If any single result is outside your lab's range, that is a question for your doctor. The estimate itself is not a diagnosis.
Why won't it give a blood age when hs-CRP is above 10 mg/L?+
An hs-CRP that high usually means an infection or a very hard training session in the days before the test. A blood age worked out from that sample would mislead you. Use a test taken when you were well and rested.