Your Birth Date
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LiveThree Ages, One Person
How it worksKorea used three different ages at once.
Korean age — 한국 나이
One at birth, plus one every January 1. This is the age people say out loud, so it runs one or two above the legal age.
Born Dec 31 → 2살 next day
Legal age — 만 나이
Zero at birth, plus one on each birthday. Since June 2023 this is the default in all laws and contracts.
Birthday passed? +1
Year age — 연 나이
This year minus the birth year, ignoring the birthday. Used for conscription, school entry, alcohol and tobacco.
Year − birth year
Which one to write down
Forms and contracts take the legal age unless they say otherwise. The counting age is for conversation, the year age for age limits.
Forms = 만 나이
Questions
03Which age should I write on a form?
Unless the form says otherwise, the legal age (만 나이). Since 2023 that is the default everywhere in law.
Why is my counting age two higher?
If you were born late in the year, you gained a year on January 1 before your birthday came around.
Does it handle February 29?
Yes. In non-leap years the birthday is treated as March 1 for the legal age, which follows the common civil reading.