Korean Age Calculator

Last updated: 2026-06-25

TL;DR

Your international (man) age is the reference year minus your birth year, minus one more if your birthday has not yet occurred this year. Since June 2023, ages in Korean administrative and civil matters default to this international age.

Example: someone born on 15 May 1990, on 25 June 2026, is 36 years old and was born in the Year of the Horse.

Enter your date of birth

Pick your birth date from the calendar.
Date to calculate the age for (default: today).

How to use

  1. Enter date of birth — pick your birth date from the calendar.
  2. Enter reference date — pick the date to calculate the age for. It defaults to today.
  3. View the result — press Calculate to see your international age, year age, traditional Korean age and Chinese zodiac.

How Korean age works and the three age systems

Since 28 June 2023, amendments to Korea's Framework Act on Administration and Civil Act mean that, unless a law, contract or document states otherwise, "age" is shown and calculated as international (man) age. International age starts at 0 at birth and increases by one on each birthday.

The three ways of counting age
TypeFormulaUsed for
International agereference year − birth year (−1 if birthday not yet passed)Legal, administrative and contractual default
Year agecurrent year − birth yearYouth-protection and military-service rules
Counting agecurrent year − birth year + 1Everyday conversation (for reference)

For example, someone born on 15 May 1990, calculated on 25 June 2026: 2026 − 1990 = 36, and because the 15 May birthday has already passed, the international age is 36. If the reference date were 1 April 2026 (before the birthday), the international age would be 35.

For a detailed explanation with examples, see the complete guide to Korean age and the 2023 reform.

Frequently asked questions (FAQ)

How is Korean (international) age calculated?

Your international age is the reference year minus your birth year, minus one more if your birthday has not yet occurred this year. For example, someone born on 15 May 1990 is 36 on 25 June 2026 because their birthday has already passed.

What was the 2023 Korean age reform?

Since 28 June 2023, ages in administrative and civil matters in Korea default to the international (man) age unless a specific rule says otherwise. The old counting age and year age systems are used less, and official documents, contracts and welfare criteria are unified around international age.

What is the difference between international age and year age?

International age depends on whether your birthday has passed this year, while year age is simply the current year minus the birth year, regardless of birthday. Year age is still used in a few Korean laws such as youth-protection and military-service rules.

How is the Chinese zodiac determined?

The Chinese zodiac (12 animals) is based on the remainder of the birth year divided by 12. This calculator uses the Gregorian birth year, so people born before Lunar New Year may belong to the previous year's animal.

Last updated: 2026-06-25