Korean Age Explained: International, Year Age and Counting Age

Ask someone's age in Korea and you might hear up to three different numbers. In June 2023 the law standardized on international age, but the other systems still appear in daily life and in a few rules.

The three systems

• International age (만 나이): the global system — 0 at birth, +1 on each birthday.
• Year age (연 나이): current year minus birth year. Everyone born in the same year has the same year age all year.
• Counting age (세는 나이), the traditional "Korean age": 1 at birth, +1 every 1 January.

Worked example

Born on 15 December 2000, on 20 October 2026:

• International age: 25 (the 26th birthday hasn't arrived).
• Year age: 2026 − 2000 = 26.
• Counting age: 27.

The Korean age calculator shows all three for any date.

What the 2023 change did

Since 28 June 2023, ages in laws, contracts and official documents are interpreted as international age unless a law says otherwise. The government's aim was to end confusion in contracts, medical care and benefits.

Where year age still applies

Some laws deliberately keep year age so everyone born in the same year is treated alike. Examples include the Youth Protection Act (alcohol and tobacco sales) and conscription under the Military Service Act. Elementary school entry is also based on birth year. When in doubt, check the specific rule.

Socially

Many people still mention counting age or year age in conversation, especially for deciding who's older (and therefore which speech level to use). Asking for the birth year is the clearest way to compare.

For an exact age in years, months and days, use the age calculator.