Korean Age Calculator
Enter your birth date and year, and the calculator computes your Korean age.
Input Information
Result
"Wait, how old am I exactly?" Solve Korea's complicated age system all at once!
In June 2023, South Korea unified its legal standard to "international age" to reduce social and administrative confusion. But in daily life, the traditional "counting age (Korean age)"—where you become 1 at birth and gain a year every January 1—is still used by custom. This calculator computes all three at once: the legal "international age," the traditional "counting age (Korean age)," and the "year age" used in laws such as the Military Service Act.
Beyond simple age calculation, it comprehensively provides age-related info such as your zodiac (12 earthly branches), legal adult status, and voting and drinking eligibility to fully answer your questions.
After the international-age unification law, confusion eased across finance, insurance, healthcare, and administration, but some laws still use "year age," so it is important to know the correct standard through this calculator.
Terminology
- International Age
- The common international standard age: 0 at birth, increasing by 1 each birthday. Unified as Korea's legal standard since June 2023.
- Korean Age (Counting Age)
- Korea's traditional method: you become 1 at birth and everyone gains a year together every January 1.
- Year Age
- The current year minus the birth year, calculated regardless of birthday. Used in some laws such as the Military Service Act and the Youth Protection Act.
- Zodiac (12 Earthly Branches)
- The Oriental zodiac of 12 animals determined by the remainder of the birth year divided by 12: Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, Pig.
- Select birth date → Enter your date of birth or birth year
- Today's date auto-applied → The reference date is automatically set to today
- Calculate → Click Calculate to see all three ages at once
Born: 2000-01-15, Today: 2026-08-25
Korean age 27, international age 26, year age 26
The three ages, how are they calculated?
1. International Age — legal standard
The common international standard and Korea's legal standard since June 2023.
- Formula: (Current year - Birth year) - (0 or 1 depending on whether your birthday has passed)
- Feature: 0 at birth, +1 each birthday
2. Korean Age (Counting Age) — tradition
Korea's traditionally used, unofficial age method.
- Formula: Current year - Birth year + 1
- Feature: 1 at birth, everyone gains a year together every January 1
3. Year Age — for specific laws
Used for regulatory convenience in some laws such as the Military Service Act and Youth Protection Act.
- Formula: Current year - Birth year
- Feature: Everyone born in a given year has the same age regardless of birthday
International age unification law, what changed?
The "International Age Unification Law," effective June 28, 2023, is a law stating that only international age may be used when calculating age in laws, contracts, and official documents.
- Finance/Insurance: Pension eligibility and insurable ages are now clearly based on international age.
- Medical/Welfare: Confusion over national health-check and welfare eligibility ages disappeared.
- Administration/Law: All official documents and legal procedures follow international age in principle.
- Caution: Some laws, such as the Elementary and Secondary Education Act (school-entry age), Military Service Act (draft age), and Youth Protection Act, still use year age.
So, when can you drink and smoke?
The Youth Protection Act defines a youth as "a person under year age 19." Therefore, from January 1 of the year you turn 19 by year age, you may purchase alcohol and tobacco. For example, someone born in 2005 is recognized as an adult from January 1, 2024, regardless of birthday.
Zodiac (12 Earthly Branches) calculation
The zodiac is determined by the remainder of the birth year divided by 12, in this order: Monkey(0), Rooster(1), Dog(2), Pig(3), Rat(4), Ox(5), Tiger(6), Rabbit(7), Dragon(8), Snake(9), Horse(10), Goat(11).
QWhat is the difference between Korean age, international age, and year age?
Korean age: 1 at birth, +1 every January 1. International age: 0 at birth, +1 each birthday. Year age: current year minus birth year, regardless of birthday.
QWhat is the 2023 Korean age law change?
Effective June 28, 2023, only international age is used in laws, contracts, and official documents. However, laws such as the Military Service Act and Youth Protection Act still use year age.
QWhich age is used internationally and medically?
International age is the global standard, used in medical care, passports, and visas. South Korea has also unified its legal standard to international age.
QHow is each age calculated based on the birthday?
Korean age: current year - birth year + 1. International age: current year - birth year (minus 1 if your birthday has not passed yet). Year age: current year - birth year.
QWhat are the drinking and voting age laws?
Under the Youth Protection Act, alcohol and tobacco can be purchased from year age 19. Voting requires age 18 or older by international age. Both apply from January 1 based on the birth year.