Traditional Korean age (counting age) starts at 1 on the day you are born and goes up by one every January 1, so it is your birth year subtracted from the current year, plus one. Someone born on June 15, 1990 has a Korean counting age of 37 in 2026, a year age of 36, and an international age of 36.
Since June 28, 2023, South Korea has used international age — the same as everywhere else — for laws and official documents. The calculator shows all three ages and when each one next goes up.
Worked example
Date of birth: June 15, 1990Age on: October 30, 2026
Traditional Korean age: 37 (세는 나이)
Born June 15, 1990: international age 36 (the birthday has passed), year age 2026 − 1990 = 36, and traditional counting age 36 + 1 = 37.
Open this example in the calculator →How to use the Korean Age Calculator
- Enter your date of birth.
- Leave "Age on" as today, or choose another date.
- Read your traditional counting age, year age and international age.
- See which age is used for what in the table below.
The three Korean ages
- Counting age (세는 나이) — 1 at birth, plus one every New Year's Day. Traditionally the time in the womb is counted, and everyone ages together at the new year. A baby born on December 31 is 2 the next day.
- Year age (연 나이) — the current year minus the birth year. Everyone born in the same year has the same year age all year.
- International age (만 나이) — 0 at birth and one more on each birthday, as used almost everywhere in the world.
So counting age is always one or two more than international age: two before your birthday each year, one after.
The 2023 change
Amendments to South Korea's Civil Act and Framework Act on Administrative Regulation took effect on June 28, 2023, making international age the standard for laws, contracts and official documents, and encouraging everyone to use it day to day. Overnight most Koreans became a year or two younger on paper.
Some laws kept year age on purpose, because they work by school year or calendar year: the Juvenile Protection Act (you may buy alcohol and tobacco from January 1 of the year you turn 19), military service (the duty begins in the year a man turns 18), and some school-entry and civil-service exam rules.
Counting age in conversation
Age matters in Korean because it decides the level of politeness people use with each other, so "how old are you?" is a common early question. Many people still give their counting age socially, and many now give their international age — if you are not sure which you are hearing, ask "만 나이?" (international age?).
The traditional East Asian way of counting age is not only Korean: China, Japan and Vietnam once counted the same way, though China and Japan reckoned the new year from the lunar calendar. The Chinese zodiac calculator uses the lunar new year too.
Frequently asked questions
How do I calculate my Korean age?
Traditional Korean (counting) age = current year − birth year + 1. In 2026, someone born in 1990 is 37 in counting age, whatever their birthday.
Does South Korea still use Korean age?
Not in law. Since June 28, 2023 international age is the legal standard. Counting age is still heard in conversation, and year age is kept for a few laws such as alcohol and tobacco sales and military service.
Why is Korean age one or two years older?
Because it starts at 1 at birth and goes up every January 1 rather than on your birthday. Before your birthday each year it is two more than your international age; after it, one more.
What is year age (연 나이)?
The current year minus your birth year. It is the age used by the Juvenile Protection Act and for military service.
How old is a baby born on December 31 in Korean age?
1 on the day of birth and 2 the next day, January 1. In international age the baby is 0 until their first birthday.