Korean School Grade Converter
What grade would this person be in, in Korea? Enter a birth year — the Korean answer is exact, because Korea groups every child born in the same calendar year together.
The Korean school year starts in March
This is the detail that breaks every mental conversion. Korean schools run March to February, not September to June. A Korean student moves up a grade in early March, roughly six months out of step with the US and UK.
So the same person can sit in two different grade numbers depending on when you ask. A child born in 2019 entered Korean 초1 in March 2026, while their American counterpart started 1st grade in September 2025 and had already moved into 2nd grade by September 2026. Neither is behind. The calendars simply do not line up, and any conversion chart that ignores this will be off by one for half the year.
Everyone born in the same year is in the same grade
Korean law is unusually clean here. Under Article 13 of the Elementary and Secondary Education Act, a child enters elementary school on 1 March of the year following the year they turn six. There is no rolling cutoff and no birthday-based placement, so a child born on 2 January and one born on 30 December of the same year are classmates for twelve years.
The US and UK do the opposite, drawing a line around September. That is why the Korean grade this tool gives you is exact, while the US grade and UK year are the closest match — a Korean student born late in the year may sit either side of it depending on the district.
The grade names tell you the stage
Korea does not count grades 1 to 12 straight through. Each stage restarts at 1, and the name carries the stage with it:
| Stage | Grades | Written as | Ages |
|---|---|---|---|
| 초등학교 Elementary | 6 years | 초1 – 초6 | 6–12 |
| 중학교 Middle | 3 years | 중1 – 중3 | 12–15 |
| 고등학교 High | 3 years | 고1 – 고3 | 15–18 |
So 고2 means the second year of high school, equivalent to 11th grade, not the second grade of anything else. This is the 6-3-3 structure, and Koreans use these short forms constantly — in conversation, in dramas, and on any form asking about a child.
고3 is a word that means more than a grade
The final year of high school has a weight that the English "senior year" does not carry. 고3 students sit 수능, the national college entrance exam, on a single Thursday in November. The country rearranges itself around it: the stock market opens late, flights are grounded during the listening section, and police give students lifts to exam halls.
If you have heard someone described as 고3 and sensed that it explained a great deal about their year, that is why.
Related tools
Work out the matching age with the Korean age calculator, count Korean numbers with the Korean numbers converter, and write a name in Hangul with My Name in Korean.
Frequently asked questions
What grade would I be in in Korea?
Take the school year, subtract your birth year, then subtract 6. For the school year beginning March 2026, someone born in 2012 is in 중2, the second year of middle school. Enter a birth year above for the exact answer.
When does the Korean school year start?
It starts on 1 March and ends in February. This puts Korean students about six months out of step with the US and UK, whose school years begin in September.
At what age do Korean children start school?
They enter 초등학교 on 1 March of the year following the year they turn six, under Article 13 of the Elementary and Secondary Education Act. Most first-graders are 6 or 7 during that year.
What does 고3 mean?
The third and final year of high school, equivalent to 12th grade in the US or Year 13 in the UK. It is the year students sit 수능, the national college entrance exam, held on a Thursday in November.
How do Korean grades map to US grades?
Counting straight through, Korean grade 1 to 12 lines up with US grade 1 to 12 by age, and with UK Year 2 to Year 13. The match is approximate because Korea groups children by calendar birth year while the US and UK cut off around September.
Are 초, 중 and 고 separate schools?
Yes. Elementary school runs six years, middle school three and high school three, and each is a separate school with its own building and entrance. Grade numbering restarts at 1 in each, which is why 중1 follows 초6.
Do all children born in the same year go to school together?
Yes. Korea uses whole calendar-year cohorts with no rolling cutoff, so children born in January and December of the same year are classmates throughout their schooling.