PhenoAge calculator: your biological age from a blood test

Questions

Is there a free PhenoAge calculator for my blood test results?

Yes. This page is a free PhenoAge calculator: enter your age and the nine markers from a routine blood test and it returns your phenotypic age in years. There is no account, and the calculation runs in your browser, so nothing you type is sent anywhere. If you upload your lab report (a PDF or a photo) at healthosx.com/blood first, the nine markers fill in here by themselves.

Can I work out my biological age from a normal blood test I already have?

Usually, yes. Phenotypic age uses markers that are on three routine tests: a complete blood count (lymphocytes %, MCV, RDW, white cells), a comprehensive metabolic panel (albumin, creatinine, glucose, ALP) and C-reactive protein. Many annual check-ups include all of them except hs-CRP. If one is missing, the result cannot be calculated; guessing a value would make the number meaningless.

What is phenotypic age (PhenoAge)?

It is an estimate published by Morgan Levine and colleagues in 2018 (Aging, 10:573–591). They fitted a mortality model on about 10,000 US adults from NHANES III using age and nine blood markers, then expressed each person’s risk as the age at which an average person had the same risk. A phenotypic age below your calendar age means your markers look like those of a younger average person.

How accurate is a biological age from a blood test?

It is an estimate for adults, built and checked on population data, not a diagnosis. In the original work phenotypic age predicted mortality better than calendar age alone, but any single draw moves with an infection, a hard workout, dehydration or a bad night, and CRP in particular can jump for a few days. Compare draws taken under similar conditions, and treat a change of a year or two as noise until a second test agrees.

Which units does the calculator need?

Either the US or the SI units most labs print: each marker has a unit switch (albumin g/dL or g/L, creatinine mg/dL or µmol/L, glucose mg/dL or mmol/L, CRP mg/L or mg/dL). The formula itself uses albumin in g/L, creatinine in µmol/L, glucose in mmol/L and the natural log of CRP in mg/dL; the page converts for you.

What lowers phenotypic age?

In the model, higher albumin and a higher share of lymphocytes lower it; higher CRP, RDW, fasting glucose, creatinine, MCV, ALP and white cell count raise it. These move with inflammation, blood sugar control, kidney and liver function and blood cell health, so the same habits that improve those markers move the number. A value outside your lab’s range is a reason to see a doctor, not to chase the score.