Probability of reaching Longevity Escape Velocity — based on age, country, and five expert-weighted hypotheses
Statistical estimates based on population-level epidemiological studies — not personal medical advice. Risk factors are combined using an additive excess model (HR = 1 + Σ(HRᵢ−1)), which empirically outperforms the naive multiplicative product for correlated behavioral factors (Mehta et al. 2017 NHANES; Khaw et al. 2008 EPIC-Norfolk). Individual relative risks from: GBD 2019, UK Biobank, Lancet meta-analyses, Holt-Lunstad et al. 2015 (social isolation), GeroScience 2025 meta-analysis (sleep).
LEV is the point at which medical technology can extend a person's remaining life expectancy by more than one year for every year that passes. Once reached, aging becomes a problem that science stays ahead of indefinitely. The concept was popularised by biogerontologist Aubrey de Grey.
It is the probability that LEV is achieved and you are still alive when it happens — weighted across five expert-calibrated scenarios for when LEV might arrive. A high number means: the most likely scenarios for LEV timing align well with your expected remaining lifespan.
Survival probabilities are based on population-average mortality tables. They reflect statistical averages across millions of people — not individual circumstances. The model does not account for:
A young person seeing a high probability should read it as: "if nothing unusual happens, the average person your age would likely be alive when LEV arrives." Individual outcomes will vary widely.
The five scenarios are weighted as follows, with explicit rationale:
These weights are a calibrated starting point, not scientific consensus. Use the hypothesis trust slider to explore how your conclusions change if you favour different experts.