What does life expectancy at birth mean?

Measurement contract

Metric key

metric.life-expectancy

Unit

years at birth (years)

Reference period

Annual; country-level measurement; observation year preserved from source

Source indicator

SP.DYN.LE00.IN

Alternative terms

life expectancy, lifespan, health, mortality, longevity

Cross-country comparison

Allowed with same-year alignment and the documented caveats

Method

WDI publishes period life expectancy from UN population data and national demographic sources, derived from life tables and age-specific mortality rates.

Interpretation limits

• This summarizes mortality conditions in a year; it does not predict how long a particular baby will live.
• It is a period life-table measure, rather than a measure of a completed birth cohort.
• Some underlying demographic estimates are interpolated and may not capture each annual event precisely.
• Missing years remain missing; the site does not extrapolate future life expectancy.