🎂 Age Calculator
Enter a date of birth to get your exact age in years, months and days, a countdown to your next birthday, and your age in the Korean age systems.
How to use the age calculator
Enter a date of birth and your age as of today appears instantly — in whole years, in years-months-days, and as a total number of months, weeks and days. To find out how old someone was (or will be) on a specific date, change the "Age as of" date: handy for a contract, an exam registration, a visa form, a retirement date or a school cutoff. The Dec 31 and Jan 1 buttons show how the Korean age systems change at the turn of the year.
How exact age is calculated
- Age in years
as-of year − birth year, minus 1 if this year's birthday hasn't arrived yet. This is the age used on US documents and in most of the world. - Months and days are counted from your most recent birthday: a whole month passes each time the same day of the month comes around; the leftover is days.
- Days lived is a plain calendar difference. If you count the day you were born as "day 1", add one — both are shown.
- Leap-day birthdays (Feb 29): in common years the age goes up on March 1 (the day after Feb 28). Some jurisdictions use Feb 28 instead, so check if it matters legally.
Example: someone born on October 10, 1995 is 30 on October 5, 2026 and turns 31 on October 10, 2026.
What is Korean age?
South Korea traditionally used a different way to count age, which is why Korean friends, K-drama characters and K-pop profiles often seem a year or two "older" than you'd expect. There are three systems:
| System | How it works | Born Dec 1, 2000 — age on Oct 13, 2026 |
|---|---|---|
| International age (man-nai, 만 나이) | 0 at birth, +1 on each birthday — same as the US | 25 |
| Year age (yeon-nai, 연 나이) | Current year − birth year; everyone ages on Jan 1 | 26 |
| Traditional Korean age (se-neun-nai, 세는 나이) | 1 at birth, +1 every Jan 1 | 27 |
After your birthday each year, Korean age is your international age + 1; before your birthday it is international age + 2. That's how a baby born on December 31 becomes "2 years old" in traditional Korean age the very next day.
Did Korea stop using Korean age?
Officially, yes. Since June 28, 2023, amendments to Korea's Civil Act and Framework Act on Administrative Regulation say that ages in laws, contracts and official documents mean international age unless a law says otherwise. In everyday conversation many Koreans still use traditional age, and a few laws still use year age:
| Situation in Korea | Age rule |
|---|---|
| Buying alcohol and tobacco (Juvenile Protection Act) | Year age — from Jan 1 of the year you turn 19 |
| Military service obligations (Military Service Act) | Year age — enlistment exam in the year you turn 19 |
| Legal adulthood (Civil Act) | International age 19 |
| Starting elementary school | March 1 of the year after the child turns 6 (international age) |
So a Korean born in 2007 can legally buy beer from January 1, 2026 (year age 19) but becomes a legal adult only on their 2026 birthday.
Tips
- Filling in a US, UK or EU form? Use the big number at the top — your international age.
- Talking with Korean friends or reading a K-pop profile? "Korean age" usually means the traditional count (the last bold row).
- Need someone's age on a past or future date? Change the "as of" date instead of doing the math by hand.
Age rules for specific programs (insurance, pensions, school entry, sports leagues, immigration) can use their own cutoff dates. Always check the rules of the organization involved. This calculator is for reference.