Biological Age Calculator

This isn't an invented scoring system with arbitrary points assigned to habits. Each factor in this calculator is tied to a specific, published mortality or morbidity association from a large-scale study, and shifts the estimate up or down from your chronological age based on the actual documented magnitude of that risk, not a guess.

What This Calculator Measures

This combines seven lifestyle and vital-sign factors, each independently linked to mortality or major disease risk in published research, into a single wellness age estimate. It's a risk-factor summary, not a biological measurement.

The Formula

Smoking status¹, physical inactivity², poor sleep³, heavy alcohol intake⁴, elevated BMI⁵, and elevated resting heart rate⁶ each add years to the estimate; consistently meeting activity guidelines and healthy vitals can subtract years. Each factor's contribution is scaled to the actual relative risk reported in its source study, not an arbitrary point value.

How This Calculator Computes Your Result

Enter your age, sex, height, weight, smoking status, activity level, sleep duration, alcohol intake, diet quality, and resting heart rate if known. We apply each factor's documented shift independently and combine them against your chronological age to produce the estimate.

How Risk Factors Convert Into Years

Turning a relative risk into a number of years requires one more piece: how much extra mortality risk a year of chronological aging itself represents. Human mortality risk rises in a well-documented, roughly exponential pattern with age, doubling approximately every 8 years in adulthood⁷, a pattern confirmed across two centuries of demographic data and used elsewhere in medicine to translate mortality risk into an age-equivalent figure.

In real terms, this is why a 66-year-old's one-year mortality risk runs roughly double a 58-year-old's, and a 74-year-old's roughly double the 66-year-old's again, each 8-year step doubles the risk.

Year-shift = 8 × log₂(relative risk)

Each factor's relative risk is taken directly from its own cited study, not estimated. A factor with a relative risk of 2 (doubling mortality risk on its own) shifts the estimate by a full 8 years, since doubled risk is, by this same logic, worth 8 years of aging. Smaller relative risks shift the estimate proportionally less.

One exception, stated plainly rather than glossed over: diet quality does not have an equivalent single named study establishing a precise relative risk the way the other six factors do. It's included as a smaller, lower-confidence modifier rather than calculated with the same log2 scaling as the other six, forcing a precise number onto a less precisely quantified factor would overstate the rigor behind it.

Why Seven Independent Studies, Not One Combined Model

Building this from seven separately validated associations, rather than one all-in-one predictive model, is a deliberate choice. Each of the underlying studies is large in its own right, several drawing on hundreds of thousands to over a million participants, and each has been independently replicated across the epidemiological literature.

Combining independently well-established risk associations is more defensible than relying on a single proprietary scoring algorithm that hasn't itself been validated against real health outcomes, which is how a lot of consumer "wellness age" tools are actually built.