The United Nations uses 60 years to refer to older people.
This line, which divides younger and older cohorts of
a population, is also used by demographers. However,
in many developed countries, the age of 65 is used as
a reference point for older persons as this is often the
age at which persons become eligible for old-age social
security benefits. So, there is no exact definition of
“old” as this concept has different meanings in different
societies.