Fans of K-dramas and K-pop often notice that Korean stars seem to be a year or two “older” than their birth year suggests. That comes from the traditional Korean way of counting age. This guide explains Korean age, why South Korea officially changed its system in 2023 and how to calculate both ages with our International Age Calculator.
How traditional Korean age works
- You are 1 year old at birth, counting time in the womb.
- Everyone gains a year on 1 January, not on their birthday.
So a baby born on 31 December is 1 at birth and 2 the next day.
Formula
Korean age = current year − birth year + 1
Someone born in 2001 is 26 in Korean age throughout 2026, whatever their birthday.
Comparison
| Born | International age on 10 Oct 2026 | Traditional Korean age in 2026 |
|---|---|---|
| 15 March 2001 | 25 | 26 |
| 20 December 2001 | 24 | 26 |
| 1 January 2010 | 16 | 17 |
The 2023 change
In June 2023, South Korea officially adopted the international age system for legal and administrative purposes, to reduce confusion. Some laws still use “year age” (current year minus birth year) for things like military service and the legal age for alcohol and tobacco. In daily conversation, many people still mention traditional age.
Other East Asian age systems
China, Japan and Vietnam historically used similar counting methods, but today they generally use international age officially.
Other ways to count age
Our international age calculator also shows:
- Age in a chosen time zone, useful near midnight or for people born abroad
- Age in Hijri (Islamic) years, which is slightly higher because lunar years are shorter
- Fun ages on other planets
For the standard calculation, use the Age Calculator. To see how many days until your next birthday, try the Birthday Countdown. Read age in Islamic years for the lunar calendar version.
Frequently asked questions
What is Korean age?
A traditional count where you are 1 at birth and gain a year every 1 January.
Does South Korea still use Korean age?
Officially it switched to international age in 2023, though traditional age is still used socially.
How do I calculate my Korean age?
Current year minus birth year plus 1.