Korean Age Calculator (Counting Age vs International Age)
One birth date, both ages side by side — and the gap Korea's 2023 switch left behind
Puts Korea's traditional "counting age" (세는 나이) and international age side by side from a single date of birth. Under the counting system you're 1 the day you're born and gain a year every New Year's Day, which is why it usually runs one or two years ahead of the international age you're used to. Since Korea unified on international age for law and administration in June 2023, the gap between the two is exactly what trips people up — so both numbers stay on screen at once. Change the reference date to compare the two ages at any point in the past or future, and see the countdown to the next birthday and its date alongside.
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How to use
- Select the date of birth.
- Change the reference date if needed (defaults to today).
- Your international age, counting age, and next-birthday countdown appear.
FAQ
- How do international age and Korean counting age differ?
- International age starts at 0 at birth and adds a year on each birthday, while the traditional Korean counting age starts at 1 at birth and adds a year every New Year's Day.
- What was the 2023 age unification?
- As of June 2023, Korean law and administration standardized on international age. This calculator shows international age by default.
- How is it calculated on the birthday itself?
- On the day of your birthday, your international age is counted as having gone up by one year.