How it works
Korea used to have its own way of counting age, and many people still talk about it. Since June 28, 2023, laws, contracts, hospitals and official documents all use international age (만 나이, man nai): the same age you have everywhere else, going up on your birthday.
The three Korean ages
| Age | How it works | Used for |
|---|---|---|
| 만 나이 (international) | 0 at birth, +1 on each birthday | Everything official since 2023 |
| 세는 나이 (counting age) | 1 at birth, +1 every January 1 | Old habit in conversation |
| 연 나이 (year age) | This year minus your birth year | Alcohol, tobacco, military service |
So a baby born on December 31 used to be "2" in Korean age the very next day. That is why Koreans sometimes gave an age one or two years higher than a foreign friend born the same year.
Where year age still counts
A few laws kept year age on purpose. Under the Youth Protection Act you can buy alcohol and tobacco from January 1 of the year you turn 19, so everyone in the same school year becomes an adult on the same day. Military service duties also go by birth year.
Saying your age
In speech, age uses native Korean numbers with 살: 스무 살 (20), 서른 살 (30). On forms and in the news you'll see Sino-Korean numbers with 세: 이십 세. Look up any number on our numbers 1 to 100 pages.
Your zodiac animal (띠) comes from your birth year, but the year changes at Lunar New Year, not January 1. If you were born in January or early February, check the date of Lunar New Year that year.
Frequently asked questions
Does Korea still use Korean age?
Not officially. Since June 28, 2023, laws and documents use international age (만 나이). The old counting age (세는 나이) is still heard in conversation, and year age (연 나이) is still used for alcohol, tobacco and military service.
How do I calculate my Korean age?
Old Korean counting age = current year − birth year + 1. Year age = current year − birth year. International age is your normal age, which goes up on your birthday.
How old do you have to be to drink in Korea?
You can buy alcohol and tobacco from January 1 of the year you turn 19, because the Youth Protection Act uses year age. For example, people born in 2007 can drink from January 1, 2026.
How do you say "I am 25 years old" in Korean?
저는 스물다섯 살이에요 (jeoneun seumuldaseot sarieyo). Age uses native Korean numbers followed by 살.
Why did Korea change the age system?
Having three different ages caused confusion in contracts, medical care and benefits. The 2023 change to the Civil Act and the Framework Act on Administration made international age the default everywhere unless a law says otherwise.
Based on: Ministry of Government Legislation, age counting law (in force June 28, 2023) · Youth Protection Act (청소년 보호법), Article 2
Last checked: 2026-10-20