Korean Age Calculator

In the traditional Korean age system, everyone is considered 1 year old at birth — the time spent in the womb counts as the first year of life. Age then increases by 1 on every January 1st, not on individual birthdays. This means a baby born on December 31st is considered 2 years old the very next day.

The traditional formula is: Korean Age = Current Year − Birth Year + 1. This applies regardless of whether your birthday has passed yet in the current year. For example, someone born in 1995 would be 30 in Korean age during 2024.

International (Western) age starts at 0 at birth and increases on each birthday. Korean age starts at 1 and increases each January 1st. Depending on when your birthday falls and the time of year, your Korean age can be 1 or 2 years higher than your international age.

Since June 2023, South Korea officially adopted the international age system for legal and administrative purposes. However, the traditional Korean age system is still widely used in everyday conversation and social contexts, so understanding it remains important.

The South Korean government standardized to the international age system to reduce confusion in legal, medical, and administrative settings where different age systems were sometimes used interchangeably. The change was intended to simplify official processes.

Korean is a hierarchical language with different speech levels based on the relative ages of speakers. Knowing someone's age helps Koreans determine the appropriate level of formality and respect to use. This is why age is commonly one of the first things Koreans ask when meeting someone new.

If you are 18 in international age, your Korean age is either 19 or 20, depending on whether your birthday has occurred yet in the current year and what time of year it is. The Korean age is always at least 1 year higher, and sometimes 2 years higher before your birthday.

Yes, Koreans do celebrate birthdays on their actual birth dates, similar to Western practice. However, since Korean age increases on January 1st rather than on birthdays, the birthday celebration is more of a personal milestone than an age-increment event in the traditional system.