What’s my biological age and how do I calculate it?

You’ve probably heard the phrase “You’re only as old as you feel”, but what if there’s a science behind that statement? That’s the idea behind biological age, a concept that’s starting to make its way around various health circles, even though it’s not yet fully standardised. Unlike your chronological age (the number of candles on your birthday cake), your biological age reflects how your body is ageing on the inside.

But is it just a buzzword? Or could it genuinely tell us something useful about our health, our risks, and even how we can extend our healthspan?

Biological age vs chronological age

Chronological age is easy: it’s the number of years you’ve been alive. Biological age, on the other hand, is an estimate of how old your body seems based on a variety of physical and physiological markers. You might be 50 on paper, but your body might feel 45… or 60.

This difference can be significant. Some researchers argue that biological age may be a better predictor of life expectancy and disease risk than chronological age because it reflects what’s actually going on at the cellular level.¹

How is biological age measured?

Your biological age is calculated using a range of biomarkers, which are measurable indicators of how your body is functioning. In one proposed method, a set of 16 different biomarkers are used to estimate biological age. These include:¹

• Grip strength

• Lung function (vital capacity)

• Neck muscle mobility

• Blood markers (like lymphocyte concentration)

• The health of cells from the lining of your mouth and eyes

• The speed of nerve responses in the eye (electroretinogram)

• Baroreflex activity (how your heart responds to blood pressure changes)

Each of these declines gradually with age (often at less than 1% per year), so measuring their levels can paint a surprisingly detailed picture of how old your body feels on the inside.

It’s not perfect science yet. This approach hasn’t been fully validated in long-term studies, and not all biomarkers are equally reliable.¹ But it’s a promising step toward making the idea of biological age more objective and potentially more useful in medicine.

Why does biological age matter?

Right now, biological age is mostly a research tool. But it’s starting to become more relevant for people looking for deeper insights into their health.

Your biological age is a way of measuring how well your body is ageing. For example, say you and a friend are both 70 years old. However, if you have strong muscles, healthy lungs, and no signs of heart disease, whereas your friend has been relatively unfit and is overweight, your body may be closer in age to someone who is 60, and your friend’s body may function more like someone in their mid 70s. 

Understanding your biological age could one day help you, and potentially your doctor, make more informed decisions about your health, like:

• How likely you are to recover after surgery

• Whether certain treatments are right for you

• What kind of exercise or diet you need to incorporate

Is biological age just another wellness gimmick?

Not exactly, but that doesn’t mean they’re not useful. A growing number of apps, check-ups, and wearables now offer estimates of your biological age using things like blood tests, DNA markers, or lifestyle questionnaires. While these tools can’t give you an exact number, they can offer helpful insights into how your body is ageing on the inside, and how your lifestyle might be influencing that process. Just remember that while it’s interesting to get an estimate, these results are best used as a guide, not a diagnosis.¹

Can you reduce your biological age?

While you can’t change your date of birth, you can influence how fast your body ages. Regular exercise, not smoking, managing stress, eating a balanced diet, and getting enough sleep are all linked to slower biological ageing.¹ In fact, many of the biomarkers used to calculate biological age improve with healthy habits.

And unlike chronological age, which only moves in one direction, your biological age might even go backwards with the right changes.

The numan take

Biological age is still a developing concept in science and medicine, but it has potential to be more than just a trendy new wellness fad. It gives us a glimpse into how our bodies are ageing and may help predict future health risks better than a birth certificate ever could.

References

1. Jackson SHD, Weale MR, Weale RA. Biological age--what is it and can it be measured? Archives of gerontology and geriatrics. 2003;36(2): 103–115.