Korean age calculator
Enter a birth date to see 만 나이 (international), 연 나이 (year age) and 세는 나이 (traditional) at once, plus which one applies where.
Advanced
Defaults to today. Change it to ask “how old was I on that day?”
Enter a date of birth.
Which age is used where?
- Everyday / most legal forms (since 2023-06-28)만 나이
- Some alcohol, tobacco, conscription or school rules연 나이 (check the official text)
- Traditional / cultural talk세는 나이
This tool is not legal advice. Always follow the agency’s own wording.
Korea used to count age differently from most of the world. Since the Age Unification Act of 28 June 2023, everyday and most legal contexts use 만 나이 (international age). This page shows all three systems from one birth date so you can see which number a form might want.
Frequently asked questions
What is 만 나이?
International age counted from your birthday. After Korea’s Age Unification Act of 28 June 2023 it is the official default in most everyday and legal settings.
What is 연 나이?
The current calendar year minus your birth year. It ignores whether your birthday has already passed this year.
What is 세는 나이?
Traditional Korean age: 연 나이 plus one. You are age 1 at birth and everyone ages up together on New Year’s Day.
Which age should I use day to day?
만 나이 for most situations. Some legal or school contexts still use 연 나이 — see the table on this page and the official text.
What did the 2023 law change?
It made 만 나이 the unified age in most areas. Traditional “Korean age” (세는 나이) stopped being the everyday default.
Which age applies for alcohol or tobacco?
Depending on the rule it may be 만 or 연. Check the current statute — this tool is not legal advice.
Which age for conscription (병역)?
The military agency may use 연 나이. Our exception table is a summary; the official notice wins.
Which age for elementary school entry?
Usually 연 나이 / school-year rules. Follow your local education office.
How are 29 February births counted?
In a non-leap year the birthday is treated as 1 March (민법-style period counting). We apply that consistently here.
How is the zodiac animal (띠) chosen?
From the birth year on the 12-animal cycle. Display only — not an astrology claim. A dedicated Chinese zodiac (띠) tool may link here later.
What does “days until next birthday” mean?
Whole calendar days until the next birthday, using the 29 February → 1 March rule when needed. It is 0 on your birthday.
Can I enter a future birth date?
No. The tool shows an error instead.
Can I change the reference date?
Yes. Use it for “how old was I on that day?”. The default is today.
Does the time zone change the result?
Only the local calendar day is used. Nothing is converted to UTC.
Is anything uploaded?
No. The calculation stays entirely in your browser.
Can I see all three ages on one screen?
Yes. 만, 연 and 세는 appear together with the exceptions table, in Korean and English — so you can compare them without switching tools.
Which age for a job or visa form?
Read what the form asks for. Most newer Korean forms want 만 나이; when unsure, follow the agency’s own notes.
Does my age change “today”?
Yes — 만 나이 goes up on your birthday; 연 / 세는 change at New Year.