About this site

Longevity.top does one thing most longevity sites don’t: it computes your actuarial age the way an insurer would — from a published period life table and peer-reviewed hazard ratios — and then shows you exactly how. Every number on this site can be traced to a citation, and the entire methodology is public.

What makes the calculator different

• Real actuarial machinery, not a quiz score. The engine runs on the published NCHS 2021 period life table and combines risk factors as dampened multiplicative hazard ratios — the same family of math used to price life insurance.
• Visible uncertainty. Your result comes with a confidence interval computed by Monte Carlo over the published hazard-ratio CIs — on the result screen, not in a footnote. A point estimate without an interval is marketing, not statistics.
• Every factor is cited and graded. Each input links to an evidence page with the underlying studies, the hazard ratio used, and an honest evidence grade. If the evidence is weak, the badge says so.
• No stored personal data. Your inputs never leave the browser — the calculation is 100% client-side. There is no account, no profile, no funnel.
• Under-promising on purpose. It is easy to build a tool that tells everyone they’ll live to 95; it is more useful to build one an actuary would sign.

Who is behind it

The site is built and maintained by an actuary with 20+ years in insurance and an MSc in Probability & Statistics — mortality here is not a metaphor; it is a thing that has been professionally priced. The longevity conversation is dominated by biologists, biohackers and supplement marketers; where a wellness site tells you a habit is “linked to longer life,” the actuarial question is: how large is the hazard ratio, over what baseline, adjusted for what, and how much of it survives the confounding? That is the lens applied to every number on this site. The methodology is public precisely so it can be checked — if you can find a genuine error in it, we want to hear about it.

Independence & disclosure

This site carries affiliate links (see the disclosure). Those links never change a number in the calculator, and there are no display ads on the results page — the moment the tool reads like a lead-generation funnel, the credibility that makes it worth anything is gone. That is a deliberate design constraint, not a courtesy.