Through a detailed lifestyle questionnaire — diet, physical activity, sleep, stress, habits, family disease history, social connections and mental state — your estimated life expectancy and biological age are calculated. The analysis identifies factors that shorten and extend life, gives personalized recommendations by category and shows the potential years gained for each recommended change.
Where it comes from
The first life table was built by John Graunt in 1662 from London burial records, and Edmond Halley refined the method in 1693 using data from Breslau. That work created actuarial science and with it the insurance industry. A life table does not predict any individual death; it states how many people out of a large group at a given age are still alive a year later. Every modern estimate of life expectancy, whether from a government statistics office or an online calculator, rests on that structure.
How the method works
An estimate starts from the national life table for your age and sex, then adjusts for the factors with measured effects: smoking, which the large cohort studies put at around ten years; physical activity; body weight; alcohol; sleep; and the presence of close social ties, which show up in meta-analyses as comparable in size to several of the physical factors. Each adjustment is an average across a population, and the spread around each average is wide.
What a reading covers
You get a figure with the factors that produced it shown separately, so you can see which of them you can act on and roughly how much each is worth. The useful part is the breakdown, not the number.
Common questions
- Can it predict when I will die?
- No. It gives an average for people who resemble you on a handful of measured factors. Individual variation around that average is enormous.
- How much does genetics count?
- Twin studies put heritability of lifespan at roughly twenty to thirty percent, which is lower than most people assume. The rest is environment, behaviour and chance.
- Is this medical advice?
- No. It is a statistical estimate. Anything about your own health belongs with a doctor who can examine you.