Korean age calculator
Birth date
Result
Since June 2023, an age in Korean law or paperwork means international age. Calendar-year age still applies to rules like military service and youth protection, and Korean age is everyday speech, so it sits here as a reference.
What this calculator does
It takes a birth date and counts age three ways, because three counts are in use in Korea at the same time. It does not say which one is right — it shows each one and where it is used.
What "Korean age" means
In the traditional Korean count you are 1 on the day you are born, and everyone gains a year together on January 1 rather than on their own birthday. A baby born on December 31 is therefore 2 the next day. This is the count English speakers usually mean by Korean age, and it is why the number can sit one or two years above the age you are used to.
The three counts
| Count | How it works | Used for |
|---|---|---|
| International age | Years since birth; goes up on your birthday | Law and official records |
| Calendar-year age | This year minus your birth year | Military service, youth rules |
| Korean age | The row above, plus 1 | Everyday talk, not official |
What changed in 2023
On June 28, 2023, amendments to Korean law took effect: when a law, a contract or an official document states an age, it means international age unless a separate rule says otherwise. Before that, the same document could be read more than one way. Individual laws that count by birth year — military service and youth protection among them — were left as they were, which is why two of these numbers can still matter at once.
Why two rows show the same number
International age and calendar-year age match in any year once your birthday has passed. That is not an error. Before your birthday international age is one lower, on your birthday the two meet, and when the year turns they split again.
Born on February 29
A common year has no February 29, so from March 1 that year's birthday counts as passed. The days to your next birthday follow the same rule.
How is the share link built
Share builds a link that carries the values you entered. Opening it fills the same fields and shows the result right away, so the person you sent it to does not have to type anything. The values are plain to see in the address, so editing the link by hand is fine too — anything out of range simply opens the empty calculator.