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The life expectancy calculator that shows its work

Answer a few questions to see your estimated survival curve. Then open the model behind it: every assumption, every source, and every number you can change.

About you

Leave blank if unsure
Sex
Don't know it? Use height and weight

Leisure activity that makes you breathe harder: brisk walking, cycling, sport. Count vigorous minutes (running, fast cycling) twice.

Calculated in your browser. Nothing you enter is sent anywhere.

Your results

Estimated age at death
78.6
Average for a 40-year-old man

A statistical average, not a prediction for you.

Years remaining
38.6
Half reach
81
Chance of 90
20%

Chance of being alive at each age

You Average 40-year-old man
0%25%50%75%100%405060708090100110Half reach 81
Reaching 80
54%
Average 54%
Reaching 90
20%
Average 20%
Reaching 100
1.1%
Average 1.1%

Not answered, so treated as average: Smoking, Body mass index, Exercise.

Experimentalv0.1.05 sourcesSources and assumptions

Adjusts US population mortality for three of the best-measured lifestyle factors: cigarette smoking (including the age you quit), body mass index and leisure-time exercise. Each effect comes from a large published study of all-cause mortality; the share of US adults in each group comes from NHANES.

Edit this model's assumptionsChange a number and the results update
Smoking
LevelHazard ratioPopulation share
Never smoked
Quit before 35
Quit at 35–44
Quit at 45–54
Quit at 55+
Quit, age unknown
Smoke now

Shares of the population from NHANES 2017-2020. The "former, quit age unknown" ratio (1.2) is the population-weighted average of the quit-age groups.

Body mass index
LevelHazard ratioPopulation share
below 18.5
18.5 to under 25
25 to under 30
30 to under 35
35 to under 40
40 or more

Shares of the population from NHANES 2017-2020 measured BMI.

Exercise
LevelHazard ratioPopulation share
below 1
1 to under 150
150 to under 300
300 to under 450
450 to under 800
800 to under 1500
1500 or more

Bands are the study's MET-hour categories converted to moderate-equivalent minutes (0, under 7.5, 7.5-15, 15-22.5, 22.5-40, 40-75 and 75+ MET-hours). Shares from NHANES 2017-2020.

Hazard ratios are rescaled so that someone with population-average exposure matches the baseline life table. Shares of the population must add up to 1 for each factor.

Evidence you can check

Every number links to the study it came from: smoking, weight and exercise from studies of millions of people.

Private by design

The calculation runs in your browser. Nothing you type is sent to a server, and there are no accounts.

Open models

Change any assumption and watch the result move. Export your version, or import someone else's.

How the estimate is made

  1. 1

    Start from national data

    US death rates by age and sex from the Social Security Administration's life table.

  2. 2

    Adjust for your habits

    Published hazard ratios scale that risk up or down, rescaled so an average person matches the national figure.

  3. 3

    Draw your survival curve

    Your chance of being alive at each age; life expectancy is the area under the curve.

Read the full method on How it works, or the exact formulas in the OLM specification.