Korean Age Calculator

How to read your three numbers

The calculator returns three ages at once, because Korea has three ways of counting and each answers a different question.

• International age (만 나이, man nai) — the age you already use at home, rising on your birthday. It is the number on Korean official forms, hospital records and contracts.
• Counting age (세는 나이, seneun nai) — the social number. It is your international age plus one if your birthday has passed this year, plus two if it has not.
• Year age (연 나이, yeon nai) — the current year minus your birth year, shared by everyone born in the same calendar year; school years are grouped on the same January-to-December line.

If they look far apart in January and close together in December, nothing is broken: the gap narrows as the year goes on.

The question Koreans will actually ask you

New acquaintances rarely ask your age outright. The opener is 몇 년생이세요? (myeot nyeonsaeng-iseyo) — "which year were you born?" — because the birth year is what people need.

Korean builds politeness into its verbs, so whether you are older, younger or the same age (동갑, donggap) decides how two people speak and what they call each other — which is why it comes up so early and is not nosy.

Being the same age does not switch the polite endings off by itself: people say 말 놓자 (mal notja), "let us drop the formal speech", and agree to it first. Sliding into casual speech uninvited reads as rude.

So memorise your birth year, not your Korean age: say the year and the other person does the arithmetic instantly.

Where each age shows up in real life

• Buying alcohol or tobacco, entering a club — staff look at the year printed on your ID. Carry your passport, or your alien registration card if you have one; foreign national ID cards are usually not recognised.
• Cinema and venue age ratings — posted as 12, 15 or 19 and checked at the door.
• Clinics, banks, immigration and insurance paperwork — international age, without exception.
• Child, student and senior discounts — international age again, so carry proof of your birth date.

Where the plus-one rule breaks down

• "My Korean age goes up on my birthday." It does not — traditional counting ages everyone together on January 1st, which is why a baby born in late December turns 2 after a few weeks of life.
• "Korean age is just international age plus one." Only once your birthday has passed this year; before it the gap is two, which is why the calculator asks for a full date.
• "The 2023 change deleted Korean age." It only fixed the age used in law and paperwork. Counting age still runs the dinner table, deciding the older-sibling term you are given: an older man is 오빠 (oppa) to a woman and 형 (hyeong) to a man, an older woman 언니 (eonni) to a woman and 누나 (nuna) to a man.

This is a calculator, not legal advice: for visas, residency or any age-linked deadline, confirm with the relevant Korean authority.

Frequently asked questions

How do I work out my counting age without a calculator?
Take the current year, subtract your birth year, then add one. That figure is your counting age, and it stays the same from January to December no matter when your birthday falls.

Which age does Korean law use when it is not international age?
Year age. Since international age was made the standard in June 2023, an age written into a law or a contract is read as international age unless the text says otherwise — but a handful of rules still run on the birth year alone, and military conscription and the youth-protection rules covering alcohol and tobacco are the ones visitors hear about.

Why does Korea count a newborn as one year old?
It comes from an older East Asian way of reckoning age, in which a baby is one from the day it is born and everybody gains a year at the New Year rather than on a personal birthday. Neighbouring countries let the system fade during the twentieth century; Korea kept it in everyday speech, which is why it was still current enough in 2023 to need a law.

How do Koreans give a baby's age?
In months. Up to roughly two years old a child's age is quoted in 개월 (gaewol, months) rather than years, and clinic check-ups and vaccination schedules are timed the same way, so none of the three age systems comes into it.