Korean Age Calculator (International, Year and Counting Age)
Work out an age the ways Korea counts it: international age, used by law since 28 June 2023, year age and the traditional counting age, with the days to the next birthday and lunar birthdays.
Three ways to count an age
| Age | How it is counted | Where it is used |
|---|---|---|
| International age (만 나이) | 0 at birth, +1 on each birthday | Civil Act and administration since 28 June 2023; contracts, medicine |
| Year age (연 나이) | This year − year of birth | Laws that say so, such as the Youth Protection Act and the Military Service Act |
| Counting age (세는 나이) | 1 at birth, +1 every 1 January | Traditional everyday use; no longer used in law |
How the ages are calculated
- Since 28 June 2023 the Civil Act (article 158) and the Framework Act on Public Administration (article 7-2) count age as international age, from the day of birth in full years, and allow months for babies under one. A law can still count by year if it says so.
- A year of age ends the day before the birthday. For someone born on 29 February that day does not exist in common years, so the year ends on 28 February and the age goes up on 1 March (Civil Act, article 160(3)).
- With a lunar date of birth, the age is counted from the matching Gregorian date in the Korean lunar calendar (KASI). The next lunar birthday is shown on its Gregorian date; a birthday in a leap month is kept on the ordinary month, and the 30th on the 29th when the month is short.
- The zodiac animal follows the lunar year of birth, which starts at Seollal. Saju often starts the year at 입춘 (around 4 February) instead.
- Everything runs in your browser. The dates you enter are not sent to LeedyBox or saved.
Source: 국가법령정보센터: 민법 제158조 · Last checked:
Source: 국가법령정보센터: 민법(법률 제19098호) 부칙 · Last checked:
Source: 국가법령정보센터: 행정기본법 제7조의2 · Last checked:
Source: 국가법령정보센터: 민법 제160조 · Last checked:
Source: 국가법령정보센터: 청소년 보호법 제2조 · Last checked:
Source: 국가법령정보센터: 병역법 제2조 · Last checked:
Source: 한국천문연구원 천문우주지식정보: 음양력 변환 · Last checked:
Wrong result? If an age is wrong, email us the dates you entered and the result you expected, so we can fix it.
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How to use
- Enter the date of birth. If you know it only in the lunar calendar, choose "Korean lunar calendar" and enter the lunar year, month and day (tick "Leap month" if needed).
- The age is calculated for today; change "Age on" to see the age on another date, such as a deadline.
- Read the international age first: it is the legal age in Korea. Year age and counting age are shown below it, with the days to the next birthday.
- For a lunar birthday, the next lunar birthday is shown on its Gregorian date, which changes every year.
Frequently asked questions
What is my Korean age now?
Since 28 June 2023 Korea uses international age in law and administration, the same age as in most countries: 0 at birth and one year more on each birthday. The older "Korean age", or counting age, starts at 1 and adds a year every 1 January, so it is one or two years higher.
What changed on 28 June 2023?
Amendments to the Civil Act (article 158) and the Framework Act on Public Administration (article 7-2) took effect. Ages in laws, contracts and official documents are now international ages unless a law sets a different rule, and babies under one can be described in months.
Where is year age still used?
Where a law says so. The Youth Protection Act excludes from "youth" anyone who has reached 1 January of the year they turn 19, and the Military Service Act counts ages by calendar year. In both cases the age changes on 1 January for everyone born in the same year.
When does someone born on 29 February turn a year older?
In leap years on 29 February. In other years the Civil Act's period rule ends the year on 28 February, so the calculator raises the age on 1 March.
How is the age counted from a lunar birthday?
From the actual day of birth. The calculator converts the lunar date of birth to its Gregorian date with the Korean lunar calendar and counts from there; the lunar birthday itself moves every year.
Is the date I enter sent anywhere?
No. The calculation runs in your browser, and the page does not save what you enter.