Definition and Calculation
Life expectancy is a period life table indicator showing how many years a person born in a given year would be expected to live, assuming that year's age-specific mortality rates remain constant. It is calculated by accumulating mortality probabilities at each age and does not account for future advances in medical technology or changes in living conditions.
Life Expectancy vs. Healthy Life Expectancy
Life expectancy measures total years of survival, while healthy life expectancy measures years lived without functional limitations. Japan's life expectancy is about 84 years, but healthy life expectancy is around 73, leaving a gap of roughly 10 years requiring care or medical support. This highlights the difference between living long and living well.
Global Disparities
As of 2023, Japan and Switzerland have life expectancies around 84 years, while some sub-Saharan African countries remain near 55. This nearly 30-year gap results from complex factors including healthcare access, nutrition, sanitation, and the presence or absence of conflict.
Limitations for Individual Prediction
Life expectancy is a population-level statistic and does not predict any individual's lifespan. When checking health rankings on MyRank, living in a high-life-expectancy country indicates a favorable environment, but personal lifestyle choices and genetic factors ultimately determine individual health outcomes.