Korean Age Calculator
South Korea has used three age counts. Traditional Korean age starts at 1 at birth and adds a year every January 1. Counting age (연나이) is this year minus birth year. International age rises on each birthday and has been the legal standard since June 28, 2023.
Before you start
Method : Calendar-year arithmetic for traditional and counting age; completed years for international age.
Checked : Dec 31 / Jan 1 boundary and birthday-eve cases tested. Birth dates 1900 or later. International age is the legal age (Act of 28 June 2023); traditional and counting ages are shown for cultural context and the laws that still use year-minus-birth-year.
Review : not independently reviewed by an expert or by the organisation whose rules are used.
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How to Use This Calculator
- Enter the birth date.
- Change the "calculate on" date if needed.
- Press Calculate.
Methodology & assumptions
- International age: completed years (Feb 29 birthdays count on Feb 28 in common years).
- Traditional Korean age: calculate-on year − birth year + 1.
- Counting age: calculate-on year − birth year.
Worked examples
Born December 31, 2025, on January 1, 2026: international 0, counting 1, traditional 2.
Born June 15, 1990, on October 5, 2026: international 36, counting 36, traditional 37.
Understanding your result
Use international age for documents. The other two are shown for cultural context and for the laws that still use counting age.
Sources & further reading
- Yonhap News Agency. S. Korea to adopt int'l age counting system starting Wednesday (June 27, 2023).Ministry of Government Legislation briefing; exceptions for conscription, alcohol/tobacco and school age.
Frequently Asked Questions
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