Korean Age Calculator: Korean Age vs International Age
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Enter a date of birth to compare the three ways age has been counted in South Korea: international age (the standard used worldwide), traditional Korean age, and "year age".
Traditional Korean age goes up for everyone on January 1, so a baby born on December 31 is 2 in Korean age the next day while still 0 in international age.
Since June 28, 2023, Korean law and official documents use international age. This page explains the difference; it is not a legal ruling on any age requirement.
Three ages by birth year in 2027
Korean age and year age are the same all year. International age is one lower until the 2027 birthday.
| Born in | International age (before → after birthday) | Korean age | Year age |
|---|---|---|---|
| 1970 | 56 → 57 | 58 | 57 |
| 1980 | 46 → 47 | 48 | 47 |
| 1990 | 36 → 37 | 38 | 37 |
| 1995 | 31 → 32 | 33 | 32 |
| 2000 | 26 → 27 | 28 | 27 |
| 2005 | 21 → 22 | 23 | 22 |
| 2010 | 16 → 17 | 18 | 17 |
| 2020 | 6 → 7 | 8 | 7 |
| 2026 | 0 → 1 | 2 | 1 |
Worked examples
Born Dec 31, 2026 — age on Jan 1, 2027
- Only one day old
- Korean age adds a year on January 1
→ International 0, Korean 2, year age 1
Born Jul 15, 2000 — age on Mar 1, 2027
- Birthday in 2027 not reached yet
→ International 26, Korean 28 (gap 2)
Same person on Aug 1, 2027
- After the birthday
→ International 27, Korean 28 (gap 1)
Born Jan 1, 2000 — on Jan 1, 2027
- Birthday and New Year on the same day
→ International 27, Korean 28, year age 27
Three ways to count age in Korea
- International age (man-nai): you are 0 at birth and gain a year on each birthday. This is the standard in Korean law and official documents since June 28, 2023, and the same age used in most countries.
- Korean age (traditional counting age, se-neun nai): you are 1 at birth and everyone gains a year on January 1. It is still heard in everyday conversation.
- Year age (yeon-nai): the current year minus your birth year. It changes on January 1 for everyone, so it is always Korean age minus 1.
Korean age is 1 year higher than international age after your birthday, and 2 years higher between January 1 and your birthday.
What changed in June 2023
South Korea unified the age used in law, contracts and public documents to international age from June 28, 2023. When a Korean law, contract or government form says "age", it means international age unless the law says otherwise.
Some rules were left on year age, according to the official government announcement: for example the age limits for buying alcohol and tobacco under youth protection rules, military service, elementary school entry and civil service exams. Insurance age is calculated under its own rules.
For an actual requirement — a visa, a school, an age-restricted purchase or a contract — check the rule that applies to you with the organization involved. This calculator only shows the three counting methods.
Sources
- Korea.net — "Koreans to get 1-2 years younger under revised age system" (June 27, 2023) — official Korean government news site: start date and exceptions
Checked 2026-10-29.
Frequently asked questions
How do I convert my age to Korean age?
Add 1 to your international age if your birthday has already passed this year, or add 2 if it has not. Equivalently, Korean age = current year − birth year + 1.
Does South Korea still use Korean age?
Not officially. Since June 28, 2023, laws and official documents use international age. Traditional Korean age is still used informally, and a few laws use year age.
Why does everyone get older on January 1 in Korean age?
Traditional Korean age counts the calendar years you have lived in, starting from 1 at birth. A new year adds a year for everyone, regardless of birthday.
What is year age (yeon-nai)?
The current year minus the birth year. It is used by some rules, for example to decide who counts as a youth for buying alcohol and tobacco and for military service.
Can I use this to check whether I am old enough for something in Korea?
No. It shows how each counting method works, not a legal decision. Requirements depend on the specific law, school or company, so confirm with them.
Is my date of birth stored?
No. The ages are calculated in your browser, and the date you enter is not stored or sent.