A single-page, browser-based longevity estimator. Answer a short questionnaire about your lifestyle, body, and wellbeing, and the calculator returns an estimated life expectancy plus a ranked breakdown of which factors are helping or hurting.
No build step, no dependencies, no tracking. Pure HTML, CSS, and vanilla JavaScript.
Open index.html in any modern browser. That's it.
To serve it over HTTP locally (optional):
python3 -m http.server 8000
# then visit http://localhost:8000index.html— page structure and formstyles.css— responsive styling (light + dark mode)script.js— calculation engine and UI logic
The calculator starts from a baseline life expectancy by sex (US averages, ~75.8 years for males and ~81.1 for females) and applies additive adjustments based on each answer. The final estimate is clamped to a sensible range (50-110 years).
Each factor is implemented as a small scoring function in script.js, so the methodology is transparent and easy to tune. Factors include:
- Lifestyle: smoking, alcohol, exercise, diet quality, sleep
- Body: BMI (computed from height and weight, scored on a J-curve)
- Health: untreated hypertension, diabetes, heart disease history, frequency of preventive care
- Wellbeing: stress, social connection, sense of purpose
Values are drawn from well-established epidemiological literature on the impact of lifestyle and health factors on mortality. They are population-level averages, not personal predictions.
This is an educational tool for self-reflection. It is not medical advice and should not replace guidance from a qualified healthcare provider. Individual results vary widely based on genetics, environment, healthcare access, and many factors not captured here.