How is biological age actually calculated?
A look at the main methods

"Biological age" isn't one single number produced by one single test. It's an estimate — and different methods arrive at that estimate in genuinely different ways, with genuinely different levels of scientific validation behind them. Here's a plain-language look at the main approaches, and why Aevum Protocol's own Biological Age feature is built on the one it is.

Why there's more than one method

There's no single, universally agreed-upon "biological age test" the way there is for, say, blood pressure. Instead, researchers have built several distinct approaches over the past two decades, each reading a different signal your body gives off as it ages — and each with its own trade-offs between accuracy, cost, and how practical it is to actually use.

The main approaches

1. 1
   Epigenetic (DNA methylation) clocks

   These read chemical modifications on your DNA that change in predictable patterns with age. GrimAge, one of the most studied versions, has shown a strong ability to predict mortality risk in research settings. The trade-off: it needs a specialised lab test that isn't yet standardised across providers, and is typically used in research rather than routine clinical care.

2. 2
   Biomarker-based clocks (PhenoAge, Klemera-Doubal)

   These combine several standard blood values — like glucose, inflammation markers, and kidney or liver function — into a single score using a published mathematical formula. PhenoAge, developed by Levine and colleagues in 2018, is one of the two most validated methods in this category, and works from bloodwork most labs already run. This is the method Aevum Protocol's Biological Age feature is built on.

3. 3
   Telomere length

   Telomeres are protective caps on the ends of chromosomes that shorten over time. Early research suggested this could measure aging directly, but the link to actual health outcomes has proven weaker and more variable than first hoped, and testing isn't well standardised between labs.

4. 4
   Functional and physical markers

   Simple measures like grip strength, walking speed, and VO2 max are increasingly recognised as strong, low-cost predictors of healthy aging — in some studies rivalling lab-based methods for predicting real-world outcomes, without needing a blood draw at all.

Why Aevum Protocol uses PhenoAge

We built the Biological Age feature in your patient profile on the Levine 2018 PhenoAge formula because it's one of the most rigorously validated methods in the biomarker-clock category, it works from bloodwork we already order as part of your care, and its published, peer-reviewed formula means the calculation is transparent and reproducible — not a proprietary black box you have to take on faith.

If you're an Aevum Protocol patient, you can see this calculated directly in your own profile — logging a lab panel shows you your biological age alongside your chronological age, tracked over time. If your assessment flagged this as an area of interest, it's worth raising at your next visit.