How Korea Counts Age
Korea has three ways of stating an age, and until 2023 people often gave an age one or two years above the one used abroad. Since 28 June 2023 the law uses international age, but year age survives in some laws and the traditional counting age in everyday talk. This guide explains each one with the articles of law behind them.
Three Ages
| Age | At birth | Goes up | Used for |
|---|---|---|---|
| International age (만 나이) | 0 | on each birthday | laws, contracts and administration since 28 June 2023 |
| Year age (연 나이) | 0 | every 1 January | laws that say so, such as the Youth Protection Act and the Military Service Act |
| Counting age (세는 나이) | 1 | every 1 January | traditional everyday use |
Year age is simply this year minus the year of birth. Counting age is year age plus one. International age is the age used in most countries: full years since the day of birth.
The 2023 Change to International Age
Two amendments of 27 December 2022 took effect six months after promulgation, on 28 June 2023:
- Civil Act, article 158: age is calculated as international age, counting the day of birth, and stated in years; under one year it may be stated in months.
- Framework Act on Public Administration, article 7-2: ages in administration follow the same rule, unless another law or regulation provides otherwise.
Since then an age in a law, a contract or an official document means international age unless a specific rule says otherwise. The change did not alter anyone's date of birth; it settled which of the ages counts.
Where Year Age Still Applies
Some laws keep their own rule, and the 2023 amendments leave those in place:
- Youth Protection Act, article 2(1): a "youth" is a person under 19, except someone who has reached 1 January of the year in which they turn 19. The rules on selling alcohol and tobacco to youths therefore change for everyone born in the same year on the same day.
- Military Service Act, article 2(2): where the act says an obligation applies "from age N", it applies from 1 January of the year the person turns N, and "until age N" lasts until 31 December of that year.
Worked Examples
| Born | On | International | Year age | Counting age |
|---|---|---|---|---|
| 15 March 2000 | 14 March 2026 | 25 | 26 | 27 |
| 15 March 2000 | 15 March 2026 | 26 | 26 | 27 |
| 31 December 2025 | 1 January 2026 | 0 (1 day) | 1 | 2 |
| 29 February 2024 | 28 February 2025 | 0 (11 months) | 1 | 2 |
| 29 February 2024 | 1 March 2025 | 1 | 1 | 2 |
The third row shows why the counting age confused visitors: a baby born on New Year's Eve was two in counting age the next day.
Birthdays on 29 February
The Civil Act counts a period of years from the starting day and ends it on the day before the corresponding day of the final year (article 160(2)). When the final month has no such day, the period ends on the last day of that month (article 160(3)). Read together with article 158, someone born on 29 February completes a year at the end of 28 February in a common year, so the calculator raises their international age on 1 March. In leap years it goes up on 29 February.
Babies and Lunar Birthdays
- Under one year, an age may be given in months: a baby born on 31 January is one month old from 1 March, because February has no 31st.
- International age counts from the actual day of birth in the Gregorian calendar. If a birthday is known only by the lunar calendar, convert the lunar date of birth to its Gregorian date first; the Korean lunar calendar of the Korea Astronomy and Space Science Institute is the reference.
- A lunar birthday falls on a different Gregorian day each year, so the day the international age goes up and the lunar birthday party are usually on different days.
Frequently Asked Questions
Is "Korean age" still used?
In law and administration, no: international age has applied since 28 June 2023. Some people still mention counting age in conversation, and a few laws count by year.
Why is my Korean counting age two years higher than my age?
Counting age starts at 1 and adds a year every 1 January. Between 1 January and your birthday it is two years above your international age; after your birthday, one year above.
Which age goes on official forms?
International age, unless the form or the law it belongs to says otherwise. Many forms ask for the date of birth instead, which avoids the question.
Does Korea count the zodiac year from 1 January?
No. The zodiac animal of a year follows the lunar new year (Seollal), and saju often uses 입춘, around 4 February.
Sources
Source: 국가법령정보센터: 민법 제158조 · Last checked:
Source: 국가법령정보센터: 민법(법률 제19098호) 부칙 · Last checked:
Source: 국가법령정보센터: 행정기본법 제7조의2 · Last checked:
Source: 국가법령정보센터: 민법 제160조 · Last checked:
Source: 국가법령정보센터: 청소년 보호법 제2조 · Last checked:
Source: 국가법령정보센터: 병역법 제2조 · Last checked: