Skip to content
Dogu SangjaToolboxAll tools

Korean Age CalculatorBeta

Enter your date of birth to get Korea's three ages at once: international age, year age and counting age, plus how a 2023 law changed which one is used.

Result

Enter your date of birth to see the result.

How to use

Enter the date of birth and a reference date to see all three Korean ages at once: international age, year age and counting age. The explanations below cover why they differ and where each one is used.

Korea’s three ages

  • International age (man-nai): starts at 0 on the day of birth and goes up by one on each birthday. This is the age used internationally.
  • Year age (yeon-nai): ignores the birthday and is simply the current year minus the birth year. A few laws, such as the Military Service Act and the Juvenile Protection Act, use this method.
  • Counting age (se-neun-nai): starts at 1 at birth and goes up by one every New Year, following an older custom. It has no legal effect.

June 28, 2023: the switch to international age

Before that date, different laws used different age systems, which caused confusion. Under the law that took effect on June 28, 2023, administrative and civil age in Korea is, in principle, unified as international age. However, cases specifically set by law, such as military service or the minimum age to buy alcohol and tobacco, still use year age.

For details, see the Korean Ministry of Government Legislation notice on the switch to international age (in Korean).

Frequently asked questions

What is the difference between international age and year age?

International age starts at 0 on the day you are born and goes up by one on each birthday. Year age ignores the birthday and is simply the current year minus the birth year. Since June 28, 2023, Korean laws, contracts and official documents have used international age by default, while a few laws such as the Military Service Act and the Juvenile Protection Act still use year age.

Is counting age still used?

Counting age (1 at birth, plus one every New Year) has no legal use in Korea. It survives mainly as an everyday custom; laws, contracts and administrative procedures only apply international age or year age.

What changed on June 28, 2023?

From that date, the age recorded in Korean laws, contracts and official documents was unified, in principle, to international age. Before it, different laws mixed international age, year age and counting age, which caused confusion. Some laws, such as the Military Service Act and the Juvenile Protection Act, still use year age unchanged.