The life expectancy of an individual or a cohort is defined as the (average) expected number of years the individual or cohort will live. Life expectancies are based on estimates and projections about future developments that affect mortality, and hence estimates may differ. Note that life expectancy refers to the total number of years lived, rather than just to the number of additional years lived beyond the current age.
Life expectancy at birth
By default, reported life expectancy refer to life expectancy at birth. For instance, reported life expectancy in Canada in 1982 means the average life expectancy of a newborn baby in Canada in 1982.