Why Korea Is Changing How It Counts Age — Explained

For most of modern history, Korea ran on two age systems. There was the international age — the one your passport agreed with — and the “Korean age,” which added a year at birth and another every Lunar New Year. A baby born on December 31 could be two years old by sunrise the following morning. It made sense if you grew up with it. It made no sense if you didn’t.

What actually changed

In 2023, Korea formally adopted the international age system across all administrative records. Hospitals, courts, government forms, age-restricted purchases — everything that touches officialdom now uses the same age system the rest of the world uses. The “Korean age” still exists in conversation. Your grandmother probably still uses it. But it no longer affects whether you can vote, drive, or buy soju.

Why two systems existed at all

The traditional system was a holdover from broader East Asian conventions. Several countries used to count age in a way that prioritized lunar calendar transitions over solar birthdays. Most of those countries moved on decades ago. Korea kept the dual system longer than most, partly out of cultural attachment, partly because the differences were small enough to ignore in daily life.

There was also a third system — “counting age” — used mostly for legal and medical purposes. That one counted you as zero at birth and ticked up on January 1 each year. It produced answers different from both the international system and the Korean age. If you ever tried to figure out how old a K-drama character was supposed to be, you may have run into this one without realizing it.

What the reform fixed

Before 2023, the gap between systems caused predictable headaches:

• Medical records sometimes used one age while school records used another.
• Foreign visitors filling out forms got tripped up by which number to write.
• Athletes competing internationally had to track two ages at once.

The reform consolidates everything around the international standard. It’s not glamorous policy work. It’s the legislative equivalent of fixing a long-standing inconsistency in a spreadsheet that touches everything else.

What didn’t change

Korean age remains common in conversation, especially among older speakers. Asking “what year were you born?” is still a more reliable way to figure out someone’s age than asking for a number, because the number you get depends on who’s counting.

The school system also continues to use a variant — kids born in the same calendar year typically enter school together regardless of their international age. That’s a different beast and isn’t going away.

Why it took so long

The push to reform predates 2023 by at least a decade. Earlier attempts ran into the same objection every time: tradition. The eventual breakthrough came when officials made the case as a quality-of-life and administrative-efficiency issue, not a cultural one. The framing mattered. Reform passed not because Korea decided the old system was wrong, but because the everyday cost of keeping it stopped being worth paying.

For most foreigners visiting Korea today, the answer to “how old am I in Korea?” is now the same as anywhere else. For Koreans, the old number lingers in conversation but no longer follows you onto a form. That’s exactly the kind of reform that sounds boring and turns out to matter.