Life Expectancy Calculator
Estimate your life expectancy based on lifestyle
About this tool
Get a statistical estimate of your life expectancy by entering your age, sex, country, and a handful of lifestyle factors—smoking status, exercise frequency, BMI range, and diet quality. The calculator adjusts the WHO/UN baseline life-expectancy figures for your country based on well-studied risk modifiers and shows you years remaining, the percentage of life already lived, and a breakdown of how each habit affects your estimate. This is a statistical model, not medical advice.
How to use
- 1 Enter your current age.
- 2 Select your biological sex.
- 3 Choose your country from the dropdown.
- 4 Fill in lifestyle factors: smoking, exercise, BMI range, and diet quality.
- 5 Click 'Calculate' to see your estimated life expectancy and years remaining.
- 6 Review the habits breakdown to see which factors have the biggest impact.
What this calculator estimates, and what it does not
Life expectancy is a statistical average: it tells you how long a typical person with certain characteristics tends to live, not how long any specific individual will. This tool starts from a published baseline — the average life expectancy for your country and sex — and then nudges that figure up or down based on a few well-studied lifestyle factors. The result is a rough projection of total years and years remaining, with a clear breakdown of what each habit contributed. It is a model for reflection and motivation, explicitly not a medical prediction.
How the estimate is built
The calculation is deliberately transparent. It takes the country-and-sex baseline and adds a fixed number of years for each lifestyle answer:
| Factor | Answer | Years added |
|---|---|---|
| Smoking | Smoker / Non-smoker | −10 / 0 |
| Exercise | Sedentary / Light / Moderate / Very active | −3 / 0 / +2 / +3 |
| BMI range | Underweight / Normal / Overweight / Obese | −1 / 0 / −1 / −3 |
| Diet quality | Poor / Average / Good / Excellent | −2 / 0 / +1 / +2 |
The adjustments are summed and applied to the baseline to give your estimated life expectancy. "Years remaining" is that figure minus your current age, and "percent of life lived" is your age divided by the estimate. Note the model never lets your estimate fall below your current age plus one year — so even a high-risk profile always shows at least a little time ahead.
A worked example
Take a 45-year-old man in the United Kingdom. The baseline male figure for the UK in the model is 79.4 years. Suppose he is a non-smoker (0), exercises moderately (+2), has a normal BMI (0), and eats a good diet (+1). The adjustments total +3, so his estimate is 79.4 + 3 = 82.4 years. Years remaining: 82.4 − 45 = 37.4. Percent of life lived: 45 ÷ 82.4 ≈ 55%. Now change one answer — he takes up smoking. That subtracts 10 years, dropping the estimate to 72.4 and remaining years to 27.4. The breakdown panel makes this single, dominant effect impossible to miss.
Why smoking dwarfs everything else
The factor with the largest weight by far is smoking, at −10 years. That is not arbitrary: large epidemiological studies consistently find that long-term smokers lose around a decade of life on average compared with people who never smoked. No other single habit in the model comes close, which is exactly the point — it shows, in concrete years, why quitting is the highest-impact change most people can make. Regular exercise (+2 to +3) and a good diet (+1 to +2) push in the helpful direction, while obesity (−3) and a sedentary lifestyle (−3) pull the other way.
Reading the country baselines
The baseline figures come from WHO/UN national life-expectancy estimates, and the spread between countries is striking. In the model a Japanese woman starts from about 87 years and a Japanese man from 81, while figures for some lower-income countries start in the 50s and 60s. Women's baselines are consistently a few years above men's across every country — a real and well-documented pattern. Because the baseline is the single biggest input, your country and sex shape the result far more than any lifestyle tweak; the lifestyle factors then personalise that starting point.
How to use the result well
- Treat it as a comparison tool, not a verdict. The most useful thing you can do is change one answer at a time and watch the number move. That isolates the impact of each habit and turns an abstract figure into a clear "what if."
- Focus on what you control. You cannot change your country baseline, but smoking, activity, weight, and diet are all modifiable — and the model shows each one's payoff in years.
- Don't over-read small differences. A one- or two-year shift is within the noise of any population model; a ten-year swing from smoking is a signal worth acting on.
Important limitations
This is a simplified additive model. Real mortality risk involves genetics, family history, specific medical conditions, income, access to healthcare, accidents, and interactions between factors that no four-question tool can capture. The factor weights are reasonable averages, not precise figures tuned to your situation, and the country baselines are national averages that may not reflect your region or circumstances. The calculation runs entirely in your browser — your age, sex, and lifestyle answers are never transmitted or stored. Use the estimate as a prompt to think about healthy habits, and rely on a doctor for anything resembling a real health assessment.