South Koreans use three ways to calculate age (Credit:

In most countries, a person's age is determined by subtracting the date of birth from the given date. However, in South Korea, an individual's age can be calculated in three different ways. A new law that took effect on June 26, 2023, aims to simplify the confusing system.

Korean age systems

A South Korean's age depends on the situation. The "International age" system, whereby a person turns a year older on their birthday, is used for legal documents like passports.

The traditional "Korean age" system is commonly used in everyday life. It deems every person one year old at birth and adds another year when the calendar hits January 1. This means a baby born on December 31 would turn two the next day.

The "calendar age" system starts with the individual being born at zero years. It then adds a year every January 1. This age is used to determine things like school eligibility and military service, which is mandatory for all South Koreans.

Not surprisingly, the three different systems cause confusion and often result in social and legal disputes.

The new law aims to simplify the age calculation system (Credit:

How will the new law help?

The new law does not address the calendar age system. However, it does replace the Korean age system with the international one. This means individuals will not be a year old when born or add a year every January 1. As a result, all South Koreans have instantly aged backward by a year or two within their social circles.

Not surprisingly, South Koreans are pleased with the change. "I was about to turn 30 next year [under the traditional age system], but now I have some more time earned, and I love it," Choi Hyun-ji told The Guardian. "It's just great to feel like you're getting younger."