Life expectancy calculator

How the estimate is calculated

The calculator starts from the remaining life expectancy at your current age, taken from the World Health Organization's global life tables for 2019 (the Global Health Observatory indicator "ex - expectation of life at age x", for males and females, interpolated between the table's age bands). Because it is a global average, people in high-income countries will typically see a higher figure in real life, and people in lower-income countries a lower one. It then applies rounded adjustments for each lifestyle and health factor, based on the general direction of published research:

• Smoking: −10 years (current), −5 years (former)
• Heavy alcohol: −4 years; moderate: −0.5 years
• Regular exercise (≥150 min/week): +3 years
• Obesity (BMI 30+): −3 years; overweight: −1 year; underweight: −2 years
• Diabetes: −6 years
• Higher education: +2 years
• Married / long-term partner: +1.5 years
• Higher income (top quartile): +2 years
• Self-rated health (Excellent): +2 years; (Poor): −5 years

The adjustments are added together and scaled down as you get older, so they never exceed the years you have left; this is a simplification. Beyond age 85 the table is extended with a simple estimate, and the result never drops below a small floor for someone who is alive today.

Sources for the direction and rough size of the adjustments: Jha et al., New England Journal of Medicine 2013 (smoking); Wood et al., The Lancet 2018 (alcohol); Moore et al., PLoS Medicine 2012 (physical activity); Prospective Studies Collaboration, The Lancet 2009 (BMI); Emerging Risk Factors Collaboration, New England Journal of Medicine 2011 (diabetes); Chetty et al., JAMA 2016 (income). The adjustments for education, relationship status and self-rated health are simplified assumptions.

Why this matters

Knowing your approximate time horizon - even as a rough estimate - is clarifying. Left is built around exactly this idea: the time you have left is finite, and seeing it clearly is the first step to using it intentionally. The life expectancy calculator gives you a number to work with. What you do with that number is up to you.

Limitations

Population-level averages cannot predict individual outcomes. Genetics, access to healthcare, location, and countless other factors are not captured here. Treat this as a rough benchmark, not a prediction. For health decisions, consult a medical professional.

See the years you have left as a grid in the life calendar.

See your life in weeks