From
Encyclopedia Britannica: "Definitions of old age are not consistent from the standpoints of biology, demography (conditions of mortality and morbidity), employment and retirement, and sociology. For statistical and public administrative purposes, however, old age is frequently defined as 60 or 65 years of age or older."
Sergei Scherbov, co-author (with Warren Sanderson) of the 2019 book
Prospective Longevity: A New Vision Of Population Aging, says a person can be considered old when his life expectancy is down to 15 years or less. In Japan, where the life expectancy for women is 88 years, a woman would not be considered old until she turns 73. In Sierra Leone, where the life expectancy for women is 72, a woman would be considered old at 57.
My own definition is much simpler: If you
feel old, you
are old.
