Life Expectancy Calculator
Estimate life expectancy from WHO baselines adjusted for your lifestyle — a population-level estimate, not a medical prediction.
Source: WHO Global Health Observatory (WHOSIS_000001) · 2021 · last verified 2026-09-12
How this estimate is derived
- Model:
- WHO life expectancy baseline adjusted by published lifestyle-mortality research
- Data:
- WHO Global Health Observatory (WHOSIS_000001) · 2021
- Implementation last reviewed:
- 2026-08-29
- Purpose:
- Educational risk estimation only; not a clinical diagnosis.
How this is calculated
Your estimate starts from the WHO's 2021 life expectancy at birth for your country and sex, then each lifestyle factor you enter adds or subtracts years based on ranges from published cohort-study research — smoking, BMI, exercise, diet quality, alcohol consumption, sleep, social connections, chronic conditions, and family history of longevity. The factor breakdown table shows exactly how much each input contributed, so you can see what's helping and what's hurting most.
The single largest lever in most published models is smoking status — quitting is consistently associated with a bigger swing in estimated life expectancy than any other individual input here, including diet or exercise. This calculator estimates biological life expectancy from lifestyle factors alone; for a related but distinct estimate that also weighs health conditions against retirement planning, see the Biological Age calculator and the Survival Probability calculator.
Frequently asked questions
- Is this a medical prediction?
- No. This is a population-level statistical estimate, built from WHO life expectancy baselines adjusted by published lifestyle-mortality research. It cannot account for your individual medical history, genetics beyond family longevity, or future medical developments — it's a general-interest tool, not a diagnosis or a medical prediction.
- How are lifestyle factors weighted?
- Each factor (smoking, BMI, exercise, diet, alcohol, sleep, social connections, chronic conditions, family history) is scored using ranges derived from published cohort studies — including Harvard T.H. Chan School of Public Health research, New England Journal of Medicine lifestyle-mortality analyses, and CDC actuarial data — then added together as years gained or lost from your country and sex baseline.
- Why did my estimate change so much from one factor?
- Some factors carry a wide possible impact — smoking and multiple chronic conditions in particular can each shift the estimate by up to 10 years in published research. The factor breakdown table shows exactly how much each input contributed.
- Can I use this in my own app?
- Yes — every calculator on Stupidly Clever has a matching REST API and MCP tool that runs the same underlying logic.
- What lifestyle factor has the biggest impact on longevity?
- Smoking typically has the largest single negative effect in most longevity models — regular smoking is associated with 8–10 years of reduced life expectancy in longitudinal studies. Regular moderate exercise and not being obese are the next most impactful positive factors.
- How does the calculator's estimate compare to life insurance actuarial tables?
- This is an educational estimate based on population-level research, not an actuarial model. Life insurers use proprietary underwriting data including medical history, family history, and specific test results. The estimate here is a useful directional tool, not a quote.