Korean Age Calculator
Works out your 만나이, 연나이 and the old 세는나이 from a birth date, on any reference day.
Since the 만 나이 통일법 took effect in June 2023, “age” in law and administration means 만나이 — but 연나이 is still used for school years, conscription and a few statutes, and 세는나이 is still what a relative means at a family gathering. This gives all three for a birth date on any reference day.
Date of birth
Age
만 나이 — completed years
36
The default in law and administration
연 나이 — current year minus birth year
36
Conscription, school entry, the Youth Protection Act
세는나이 — the traditional count
37
Everyday conversation
Days lived
13,328 days
Months
437 months
186 days to the next birthday (2027-05-15)
Lunar birthday and animal sign
Lunar date
1990, month 4, day 21
Animal sign
horse
경오년
Which boundary marks the change of sign depends on the tradition — lunar new year or 입춘. This uses lunar new year, so a birthday in January or February may be given differently elsewhere.
Ages the law attaches to
- Starting primary school1997-03-02The March after turning 6 (초·중등교육법, Elementary and Secondary Education Act)
- The vote2008-05-15만 나이 (공직선거법, Public Official Election Act)
- Driving licence (class 1 and 2 ordinary)2008-05-15만 나이 (도로교통법, Road Traffic Act)
- 국민연금 contributions begin2008-05-15From 18 (국민연금법, National Pension Act)
- Age-restricted films2009-01-01연 나이 (청소년 보호법, Youth Protection Act)
- Buying alcohol and tobacco2009-01-01연 나이 — from 1 January, whatever the birthday (청소년 보호법)
- Majority under the Civil Act2009-05-15만 나이 (민법 §4, Civil Act, art. 4)
- 국민연금 payments begin2055-05-15From 65 for anyone born in 1969 or later
- 기초연금 eligibility2055-05-15From 65 (기초연금법, Basic Pension Act)
- Free metro travel2055-05-15From 65; local authorities may differ
Some of these are 만 나이 and some are 연 나이. Alcohol and tobacco are from 1 January of the year you turn 19 regardless of your birthday; the vote is from the birthday itself. Mixing those two up is the commonest misunderstanding there is.
How to use it
Enter the birth date
The reference day defaults to today and can be set to any date — useful for “how old will they be on the day of the exam”.
Read the three numbers
만나이 increments on the birthday, 연나이 is the current year minus the birth year, and 세는나이 is that plus one. In January the three can be two years apart.
Use the one the form asks for
Unless it says otherwise, an official form means 만나이. Where a rule is written as “해당 연도에 N세가 되는 사람”, that is 연나이 and the birthday does not matter.
Common questions
Did 세는나이 stop existing in 2023?
No. The law fixed what “age” means in statutes and administration; it did not change how people speak. 세는나이 is shown here because it is still the number a conversation is likely to be about.
What about someone born on 29 February?
In a non-leap year 만나이 increments on 1 March, following the convention that the age is attained the day the corresponding date would have passed.
Can I enter a lunar birth date?
Convert it to the solar date first with the lunar calendar tool. Age is counted against the solar calendar, and a lunar date entered as if it were solar gives an answer that is wrong by weeks.
Feed it from
Date Difference
Counts days, weeks, months and years between two dates, with a D-day view and business-day option.
Zodiac & Star Sign
Gives the Korean animal sign, the sexagenary year name and the star sign for a birth date.
Housing Subscription Score
Scores the 84-point housing subscription total from dependants, no-home period and account age.
Business Registration Number Validator
Checks the 10-digit check sum of a Korean business number and can bulk-validate a pasted column.
Next
These accept what this tool produces, so the result can go straight in.
Date Difference
Counts days, weeks, months and years between two dates, with a D-day view and business-day option.
Social Insurance Calculator
Splits national pension, health, long-term care and employment insurance between employee and employer.
Lunar Calendar Converter
Converts between lunar and solar dates, handling leap months, and lists a lunar birthday for years ahead.
Zodiac & Star Sign
Gives the Korean animal sign, the sexagenary year name and the star sign for a birth date.
Annual Leave Calculator
Works out how many paid leave days have accrued by joining date or fiscal year, including the first-year rule.
Capital Gains Tax Estimator
Estimates capital gains tax on a house, land or 분양권 from prices, dates and expenses — 장기보유특별공제 표1/표2, the 12억 1세대 1주택 rule, short-term rates and the 조정대상지역 surcharge you choose.