Lunar age calculator: Chinese and Korean age in one place
This free lunar age calculator shows the age people mean when they say “lunar age” — the Chinese 虚岁 (xūsuì), where a baby is one at birth and everyone gains a year at Chinese New Year — next to the Korean counting age, the Korean “year age” and the international age used on passports. Enter a date of birth and it also gives the lunar birth date, the zodiac animal of the lunar birth year, and the date of the next lunar birthday.
A table shows how each age changes through the year, so it is easy to see why a person can be two years “older” in lunar age for a few weeks between Chinese New Year and their birthday. Lunar dates come from the Hong Kong Observatory tables for 1901–2100, the same data used by the Chinese lunar calendar converter.
How to use the Lunar Age Calculator
- Enter the Date of birth (Gregorian). Tick Remember my birth date to keep it on this device only.
- Leave Age on as today, or pick another date — press Today to return.
- Read the Chinese lunar age in the large box and the Korean age, international age and Korean year age below it.
- Check your lunar birth date, zodiac animal and next lunar birthday, and the table of age changes through the year.
- Press Copy ages to paste the results elsewhere.
Lunar Age Calculator features
Four ages at once
Chinese xusui, Korean counting age (세는 나이), Korean year age (연 나이) and international age (만 나이).
Lunar birthday calculator
Your birth date in the Chinese lunar calendar, the next lunar birthday in the Gregorian calendar, and how many days away it is.
Leap-month births
Someone born in a leap month celebrates in the regular month of that number when the year has no matching leap month.
Year timeline
When New Year’s Day, Chinese New Year and your birthday change each age in the chosen year.
Private
Nothing is sent anywhere; the optional remembered birth date stays in this browser.
How lunar age and Korean age are counted
Chinese lunar age (虚岁): one at birth, plus one at every Chinese New Year. It equals the lunar year of the date minus the lunar year of birth, plus one. A baby born the day before Chinese New Year is two the next morning. Korean counting age works the same way but adds the year on 1 January (traditionally at Seollal, the lunar new year), so it is the Gregorian year difference plus one. Korean year age is just the year difference; it is still used for military service and some youth-protection rules. International age counts completed years from the birthday.
For example, someone born on 20 January 1990 — before Chinese New Year 1990 (27 January), so in lunar year 1989, the Year of the Snake — is, on 19 October 2026, 36 in international age, 37 in Korean age and 38 in Chinese lunar age. Japan’s old kazoedoshi count matched the Korean counting age; Vietnam’s tuổi mụ adds the year at Tết.
| Born | On | Lunar (虚岁) | Korean | International |
|---|---|---|---|---|
| 20 Jan 1990 | 19 Oct 2026 | 38 | 37 | 36 |
| 31 Dec 2025 | 1 Jan 2026 | 1 | 2 | 0 |
| 16 Feb 2026 | 17 Feb 2026 | 2 | 1 | 0 |
| 15 Jun 1985 | 15 Jun 2026 | 42 | 42 | 41 |
Korea’s 2023 age law and other limits
Since 28 June 2023, amendments to South Korea’s Civil Act and Framework Act on Public Administration make international age (만 나이) the default in laws, contracts and official documents; counting age is now a social custom only, and some laws still use year age. Chinese official documents have always used completed years — 虚岁 is used for tradition, horoscopes and some celebrations.
Chinese New Year here follows China Standard Time (UTC+8). Korea calculates its lunar calendar for UTC+9 and Vietnam for UTC+7, so Seollal or Tết occasionally falls a day — rarely a month — away from Chinese New Year; for 2027 Korean holiday calendars list Seollal on 7 February, a day after Chinese New Year. Births before 19 February 1901 and dates after 2100 are outside the tables. For an exact age in years, months and days use the age calculator, and to look up the zodiac sign the Chinese zodiac calculator.
Lunar Age Calculator FAQ
How do I calculate my lunar age?
Enter your date of birth. The large number is your Chinese lunar age: one at birth plus one for each Chinese New Year since. It is usually one or two more than your international age.
What is my Korean age?
Korean counting age is the current year minus your birth year, plus one. Since June 2023 Korean law uses international age instead, but the counting age is still heard socially.
Why is my lunar age two years more than my real age?
Lunar age starts at one and adds a year at Chinese New Year. Between Chinese New Year and your birthday you get both extra years, so the gap is two.
How do I find my lunar birthday this year?
The calculator converts your birth date to the lunar calendar and lists the next date that lunar month and day come round, with the number of days until then.
Is lunar age the same as the Chinese zodiac year?
They use the same lunar year: if you were born in January or early February before Chinese New Year, both your lunar age and your zodiac animal belong to the previous year.
Does the lunar age calculator store my birth date?
Only if you tick Remember, and then only in your own browser’s storage.