Korean age calculator

See your international age, year age and traditional Korean counting age side by side — and which one is used where since the 2023 change.

South KoreaFree, no sign-up

Before you use it

Works well for

  • Understanding the three Korean age systems
  • Visa, school and travel paperwork
  • Finding your zodiac animal (띠)

Not the right tool for

  • Legal advice on which age applies to a specific case
  • Lunar birthdays — enter the solar (Gregorian) date

Three ways to count age

  • International age (만 나이): the number of birthdays you've had — the same as everywhere else.
  • Year age (연 나이): the current year minus your birth year, ignoring the birthday.
  • Counting age (세는 나이): the traditional system — you're 1 at birth and everyone gets a year older on 1 January.

What changed in 2023

Since 28 June 2023, South Korean law uses international age as the standard for contracts, official documents and administration. A few laws still use year age — military service, the Youth Protection Act (which sets the age for buying alcohol and tobacco) and school entry — and counting age is still common in everyday conversation.

Frequently asked questions

Why was I 'two years old' at a few days old?

Under counting age, a baby born on 31 December turned 2 the next day, on 1 January. That's one reason Korea switched to international age.

Which age do I use in Korea now?

International age for almost everything official. Year age for military service and youth protection rules. Counting age only informally.

Is my birth date stored?

No. Everything is calculated in your browser.