Korean Age Explained: International Age & the 2023 Reform

Last updated: 2026-06-25

What the Korean age reform changed

Korea long had three coexisting ways of counting age, which caused a lot of confusion. There was "counting age" (the traditional Korean age), where you are 1 at birth and gain a year every 1 January; "year age", which is simply the current year minus the birth year; and "international age", which is based on your birthday. The same person could be referred to by two or three different ages depending on the situation, leading to constant disputes and mistakes in healthcare, welfare, contracts and the workplace.

To end the confusion, the government amended the Framework Act on Administration and the Civil Act so that, from 28 June 2023, international age is the default. Now, if a law, contract or official document simply says "age" without a special rule, that age means international age. Because it is interpreted as international age even without explicit labeling, using international age has become the standard even in everyday life.

How to calculate Korean age yourself

International age is surprisingly simple. The key question is: "Has this year's birthday already passed?"

• If your birthday this year has passed: current year − birth year
• If your birthday this year has not passed yet: current year − birth year − 1

For example, take someone born on 10 March 2000, calculated on 25 June 2026. 2026 − 2000 = 26, and because the 10 March birthday has already passed, they are 26. If you calculate the same person on 1 February 2026 (before the birthday), they are 25. In other words, international age increases by one on the birthday itself.

International age vs. year age vs. counting age

All three use the word "age", but they are calculated differently. International age is based on the birthday, so people born in the same year can have different ages depending on whether their birthday has passed. Year age depends only on the year, so it is easy to compute but can be a year higher than international age. Counting age makes you 1 at birth and adds a year for everyone at the new year, so it is one or two years higher than international age.

For instance, a baby born on 31 December becomes 2 in counting age the very next day (1 January), but in international age only a single day has passed, so they are 0. This kind of extreme gap is exactly why the age unification was needed.

What stays the same after the reform

The age reform did not change everything. To reduce social confusion and administrative cost, some systems still use "year age". The main examples are:

• Elementary school enrollment — the existing rule, where children enroll in March of the year after they turn 6, is kept.
• Military service — the Military Service Act uses year age (year − birth year) for conscription examinations and the like.
• Youth protection — under the Youth Protection Act, the age for buying alcohol and tobacco is "someone who turns 19 (international) within the year", which is year-age based. In 2026, for example, people born in 2007 onward can purchase.
• Civil-service exams — some exams may also use year age for eligibility.

So when you check "your age", it is important to first know which system the rule uses. Most are international age, but the exceptions above use year age.

Everyday changes brought by international age

Since the reform, some everyday changes are noticeable. Retirement age, senior welfare benefits (senior discounts) and wage-peak systems are all based on international age. Eligibility ages for insurance, medication-dosage age thresholds and "65 and over" discount labels are also interpreted consistently as international age. In the past people would wonder, "My counting age is 66, so do I qualify for senior benefits?" — now you only need to consider international age.

When asked your age, giving your international age is the standard. That said, counting age is still used in casual conversation, so it is a good habit to always use international age in official documents and contracts.

Check your Korean age quickly

If doing the math is a hassle, just enter your date of birth and a reference date in the Korean age calculator. It shows your international age, year age, counting age and your Chinese zodiac all at once. To see your zodiac and star sign together, use the Chinese zodiac & star sign tool, and to count working days between two dates, use the business day counter.

Summary

• Since 28 June 2023, ages in administrative and civil matters are unified to international age.
• International age = current year − birth year, minus 1 if the birthday has not yet passed.
• School enrollment, military service, youth-protection rules and the like still use year age.
• "Age 65+" thresholds for senior discounts, retirement and discounts are all interpreted as international age.

Last updated: 2026-06-25