Korean Age Calculator
Korea has three ways of counting age. Enter a birth date to see all three side by side, and which one people and laws actually use. Everything is calculated in your browser.
The three ages, and when each one is used
| Age | How it is counted | Where you will meet it |
|---|---|---|
| International age 만 나이 (man nai) | Starts at 0 at birth and goes up by one on every birthday. | The legal and administrative standard. A revised law applying it across judicial and administrative areas took effect on June 28, 2023. |
| Korean age 세는 나이 (seneun nai) | You are 1 at birth, and everyone gets one year older on January 1. | The traditional way of counting. You may still hear it in everyday conversation. |
| Year age 연 나이 (yeon nai) | Current year minus birth year. Goes up on January 1, regardless of birthday. | Kept by some rules as an exception, as reported in 2023: buying alcohol and tobacco, military enlistment, civil service exams and elementary school entry. |
What this means in practice
When someone in Korea asks how old you are
Since June 28, 2023, the international age is the official standard. Korean age was the traditional way of counting, so if two numbers don't match in a conversation, it is worth asking which way of counting the other person means. This calculator shows both so you can compare.
Alcohol and tobacco
According to Korea Herald reporting at the time of the 2023 change, the legal age for buying alcohol and tobacco stayed on the year-of-birth method. The report gave the example that people born in 2004 could buy alcohol and tobacco in 2023 regardless of their birth month. In other words, the line is drawn by birth year, not by your birthday. Rules can change, so check current regulations if it matters.
Why your age "drops" by one or two years
Korean age is ahead of international age by one year after your birthday, and by two years between January 1 and your birthday. That gap is exactly what the 2023 change removed from official use.
Examples
| Born | As of | International | Korean | Year |
|---|---|---|---|---|
| 2000-08-15 | 2026-03-01 | 25 | 27 | 26 |
| 2000-08-15 | 2026-10-01 | 26 | 27 | 26 |
For people born on February 29, this tool counts the birthday as reached on March 1 in non-leap years.
FAQ
Is Korean age still used officially?
Not as the general standard. Since June 28, 2023, the international age is the standard in judicial and administrative areas, though some specific rules (such as those listed above) are excluded.
Why do Korean age and year age differ by one?
Korean age counts the year you were born as year 1. Year age simply subtracts your birth year from the current year, so it is always one less than Korean age.
Is my birth date sent anywhere?
No. The calculation runs entirely in your browser.
Sources
- Korea.net – Koreans to get 1-2 years younger under revised age system (June 27, 2023)
- The Korea Herald – Korea starts using int'l age system, but exceptions remain (June 27, 2023)
This page explains how the ages are counted. It is not legal advice.