Korean Age

The aging system in East Asia differs from 'international' age in that the age of a person is counted as the time when someone is in the womb as 'zero', and the moment they are born they are one years old or in their 'first year'. All Koreans' age will go up one year at the lunar new year, which means that a baby born on the 31st December could be two years old when they are a day old internationally. Because of this korean partents will refer to their children's age through months for the first couple of years of their life. Koreans still celebrate their actual birthdays though, with the 100th day after a baby's birth and their first birthday being specially celebrated due to high infant mortality in the past.

Each year of Korean age is called 'sal' (살), for example a person is one sal in the first year of their life, and ten sal in the tenth year of their life. International age is referred to as 'man-nai' (만나이) which literally means 'full age' (with man (만) meaning 'full' and 'nai' (나이) meaning 'age').

This system was originally used as a way to keep track of generations, though this usage has slowly died out in recent years. However, Koreans will often refer to their age by the year they were born, for example saying that they're "'92". Having same-age friends born in the same year often means automatic closeness between individuals, which can create a year 'line' in groups or among celebrities who are close friends and born in the same year.

Age Chart
Below is a quick chart for easy reference for Korean ages based on birth year.