Culture KOREA 101 Lost in translation

Why I get a year older upon arriving in Korea? How many Korean Ages are there?


And nope, the sliding door you just came out of at the Incheon International Airport was not a time-travel portal. Let’s find out the reasons behind this mad science, but brace yourself because there are THREE different age-counting methods available in Korea.


First batter up! It’s called man-nai 만나이 (man means “full” and nai means “age”). As you might have guessed, you get a year older only after a full year or 12 months, or 365 days have passed since your last birthday. This is how most countries count age, so let’s call this the “International Age” 

Next is seneun-nai 세는 나이 (seneun means “counting” and nai “means “age”), so it literally means “counting/counted age.” This is how it works. First, you are 1-year-old as soon as you are born and every year you get a year older. This counting method is unique to Korea, so foreigners call this the “Korean Age.” Let’s put this in perspective.

Suppose you were born on December 31st, 2019. The very first day of your life, you are

man nai – 0-year-old
seneun nai – 1-year-old (you’re 1 year old as soon as you’re born)

A day later, it’s a new year. On January 1st, 2020, you are 

man nai – still 0-year-old
seneun nai – 2-years-old (you get a year older with the year change)

On your first birthday, December 31st, 2020, you are

man nai – finally 1-year-old
seneun nai – still 2-years-old (birthdays don’t add a year)

Again, with the year change a day later, on January 1st, 2021, you are 

man nai – still 1-year-old
seneun nai – 3-years-old (you get a year older with the year change)

A graphical representation of Korean age using quantum physics and differential and integral calculus.
A graphical representation of Korean age using quantum physics and differential and integral calculus.

As you can see, the two babies born on the exact same date can have an age difference of up to 2 years! Not a good news to those sensitive to their age, and from a practical point of view, it’s not a head start but a disadvantage because putting 1-month-old baby and 11-month old baby or 13-month-old baby and 23-month-old baby in the same bracket isn’t fair considering what difference a day makes for babies. 

Then where did this practice come from? There are various theories regarding the origin of the “Korean age“. Some claim that recognizing the fetus as a human being is the reflection of the humanistic perspective of the ancestors, while some argue that it’s just a system based on the lunar calendar. While there’s no historical record to provide a cut-and-dry answer, one thing is for sure, this method was widely used not only in Korea but also in many other countries across Asia. China, Japan, Vietnam, and Mongolia were among them, but the system has long been abolished except for in Korea. 

But here’s a twist – in Korea, the man nai, or the “International Age,” is actually the only legal age counting method, but the seneun nai is just so deeply embedded in the daily lives of the Korean people, it’s extremely difficult to prohibit the use. In 1962, when Korea switched from the traditional Dangun Year (named after the legendary founder of Gojoseon 고조선, the first Korean kingdom) to the Domical (Western) Year system, the man nai-only rule was ordered by the government, but to no avail. 

RELATED: Who founded Korea? How did Korea begin? Is it true that Koreans are descendants of bears…?

Why do I get a year, or even two years older when I land on Korean soil? How many "Korean Ages" are there? Ugh!
Hilarious Korean age meme
(Source: Internet)
Why do I get a year, or even two years older when I land on Korean soil? How many "Korean Ages" are there? Ugh!
Hilarious Korean age meme Made by thrembo

Okay, so much for that. Let’s talk about the third kind now. Called yeon nai 연나이 (yeon means “year” and nai means “age”), it refers to the counting of age by subtracting your birth year from the current year. This method is used as a standard for some laws, such as the Juvenile Protection Act and the Military Service Act. For example, regardless of your birth date, if you were born in 2001, you become 19 years old on January 1st, 2020. It’s used for the convenience it provides. By grouping everyone by the year, it’s easier to see if someone meets certain criteria. It’s different from how ID-checking is done in the U.S. To be able to purchase tobacco, you would have to be 18, and the birth date matters too. But in Korea, as soon as your 18th year starts, you’re automatically qualified. 

Although more options are better in many situations, the co-existence of multiple age-counting systems isn’t quite the case. In fact, it results in high social costs and frequent administrative errors, not to mention the nuisance of having to put extra effort to find out what age one’s referring to when people meet for the first time! So jjajeungna 짜증나 (annoying)!

RELATED : How old are you? Why do Korean people ask for your age at the first encounter? No need to panic! Here’s why.

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