How it works
Baseline. Mortality by age follows a Gompertz–Makeham curve, μ(x) = A + B·eCx, originally fitted to Statistics Korea's 2024 complete life table (men: A = 0.00045481, B = 3.37193×10⁻⁶, C = 0.1198262; women: A = 0.00030512, B = 2.90104×10⁻⁷, C = 0.1420988). For each country and sex the page solves for a single factor k and uses μ(x) = k·A + √k·B·eCx, so that the model's life expectancy at birth matches the UN figure below to within 0.1 years (checked in your browser when the page loads). Scaling the age-independent part more than the old-age part reflects that countries with lower life expectancy lose more years to deaths at younger ages.
Health age converts your combined risk into years: since the risk of dying rises by about 12–14% for each year of age, a risk ratio R adds ln(R) ÷ C years. Doubling your risk adds roughly 5–6 years. Life expectancy is your current age plus your expected remaining years, assuming you have reached your current age, with the adjusted mortality rates.
Baseline life expectancy at birth by country
| Country | Men | Women | Model k (men / women) |
|---|
Source: United Nations, Department of Economic and Social Affairs, Population Division (2024). World Population Prospects 2024, medium-variant life expectancy at birth for 2026 (population.un.org/wpp), as tabulated by StatisticsTimes. Period life expectancy describes current death rates, not a guarantee for any one person.
Risk factors and evidence
| Factor | Risk ratio used | Evidence |
|---|---|---|
| Smoking | 1.1–2.8 | Current smokers have 2–3× the death rate of never-smokers and lose about 10 years on average; quitting before 40 recovers most of it (Jha et al., NEJM 2013). |
| Body mass index | 1.0–1.6 | Lowest risk at roughly BMI 22.5–27.5 with higher risk for underweight and severe obesity (Zheng et al., NEJM 2011; Global BMI Mortality Collaboration, Lancet 2016). |
| Waist size | 1.2 | Abdominal obesity raises risk independently of BMI. Thresholds: men ≥102 cm (40 in), women ≥88 cm (35 in); for Asian countries men ≥90 cm, women ≥80 cm (85 cm for Korea). |
| Exercise | 0.88–1.35 | 150+ minutes a week of moderate activity lowers mortality by about 20–30% (WHO physical activity guidelines 2020). |
| Sleep | 1.0–1.3 | Short sleep about 1.12×, 9+ hours about 1.3× (Cappuccio et al., meta-analysis, Sleep 2010). |
| Alcohol | 1.0–1.6 | Life expectancy falls above about 100 g of alcohol a week — roughly 7 US or 12 UK drinks (Wood et al., Lancet 2018). |
| Blood pressure & sugar | 1.1–1.8 | Untreated hypertension and diabetes are leading causes of cardiovascular death. |
| Social connection | 1.0–1.3 | Social isolation raises mortality by about 30% (Holt-Lunstad et al., meta-analysis 2015). |
| Long-lived parents & grandparents | 0.75–1.0 | Parental longevity is linked to lower cardiovascular mortality in offspring (Atkins et al., JACC 2016). |
| Early family history, secondhand smoke | 1.15–1.3 | Early heart disease in close relatives and secondhand smoke at home both raise risk. |
Risk ratios are multiplied together and capped at 0.55–5× overall to allow for overlap between factors. Studies differ, so representative values are used. The model cannot capture child mortality separately, so in countries where many deaths happen in childhood (e.g. Nigeria) adult estimates are approximate.
Frequently asked questions
- How accurate is a life expectancy calculator?
- It gives a statistical average for people with similar habits and risk factors, not a prediction for you. Real lifespans vary widely, so treat the result as a guide to which habits matter most.
- What is health age?
- Health age is the age at which an average person of your sex has the same risk of dying as you do, given your habits and family history. Because mortality rises about 12–14% per year of age, doubling your risk adds roughly 5–6 years of health age.
- Is my face photo uploaded?
- No. The optional face-age estimate runs entirely in your browser with the open-source face-api model. The photo never leaves your device and is not used in the health age calculation.
Face age: @vladmandic/face-api 1.7.15 (MIT license), processed on your device.