How Korean Age Works: Understanding the Korean Age System

In South Korea, a unique age calculation system has been used for centuries. Under the traditional Korean age system, everyone is 1 year old at birth, and everyone ages a year on New Year's Day rather than on their birthday.

This means a baby born on December 31st becomes 2 years old the very next day (January 1st), despite being only 1 day old chronologically.

In 2023, South Korea standardized most legal ages to the international system, but the traditional Korean age is still used in social contexts.

To calculate Korean age: (Current Year - Birth Year) + 1. If your birthday has passed in the current year, some systems use: Current Year - Birth Year.

For example, if you were born in 1995 and it's 2026: your Korean age is (2026 - 1995) + 1 = 32, while your international age is 30 or 31 depending on whether your birthday has passed.