The Korean age calculation system is different from the chronological system which is adopted by most of the countries in the world. The age calculated using the Korean system, the Korean age, is 1 or 2 years older than the age calculated under the chronological system.
Under the chronological system, your age (the “actual age”) represents the actual length of time that you have lived after you were born. For example, if you were born on 31 December 2014 and today is 12 January 2015, you are just 12 days old, and you will be 1 year old on your birthday on 31 December 2015.
Under the Korean system, you are already 1 year old when you are born because the Koreans also take into account the time you spent in your mother’s womb (though in fact that period of time is not more than 10 months). Then, you are 1 year older on 1 January instead of your birthday every year. Therefore, although you may hold a birthday party to celebrate on your birthday, your birthday is not taken into account when calculating your age under the Korean system. For example, if you were born on 31 December 2014, you were already 1 year old on that day. On 1 January 2015, you gained 1 year so you are already 2 years old today (i.e. 12 January 2015). Your age will not change on your birthday, i.e. 31 December 2015, so you will remain 2 years old then.
Therefore, depending on the date on which you calculate the age, your Korean age is 1 or 2 years older than your actual age. If you calculate the age on a date before your birthday, your Korean age will be 2 years older than your actual age; if you calculate the age on a date on or after your birthday, your Korean age will be 1 year older than your actual age.
Actually, for legal purposes, Koreans use the actual age instead of the Korean age. To avoid confusion, they may put the word 만 (man), which means “full”, before the age to make it clear that they are using the actual age.
Given the differences between the Korean age and the actual age, while I was in South Korea, when talking about age with Koreans, I used the word 만 before the age to indicate that I was talking about the actual age or I told them the year in which I was born instead to avoid confusion.
Reminder: The next blog post will be published on 14 January 2015. Watch this space!
References:
“[Ask Hyojin] What is “Korean age”?“, TalkToMeInKorean, 2013-01-24
Korean Culture Blog 
I never knew that you could use 만 before to say your actual age ! Actually, I heard a few people say it but never even thought about why they used that word before the age. LOL This explains it 🙂
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Thanks for your comments. I also only learnt about this when I studied Korean in Seoul. That’s why I share it with others on my blog.
Hope you enjoy reading my blog posts.
Cheers
Kalbi
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I’m still a bit confused.. So when I was born on March 12th in 1995, I was one year old already right? Then on January 1st 1996, I turned 2 but in March 12th 1996 I stayed 2 years old?
And how about the ‘early’ born case? I’m really curious but can’t seems to understand it well 😦
Thank you before!~
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Your understanding re your Korean age above is right. Actually, the Korean system is very straightforward – you are one year old when you are born (no matter how long you had been in your mother’s womb) and on 1 January every year you gain one year. Just ignore your actual birth date in calculating your Korean age.
The same method of calculation of Korean age applies to early born case since it doesn’t matter how long a person had been in his/her mother’s womb.
Hope this clarifies 🙂
Cheers
Kalbi
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