Age calculator
Calculate international, year-based and Korean counting age at once. You'll also see the weekday you were born, your zodiac animal, the iljin of that day, your lunar birthday and how many days you've lived.
If you only know your lunar birthday, convert it first with the Lunar–Gregorian converter.
Anniversaries
Highlighted rows are days still to come.
The two characters of your birth day describe you
See the full picture — your day pillar plus the other six characters — in Mutal Unnie. Just enter your birthday to get started.
Get the app for iPhone & AndroidWhy there are three kinds of age
Someone born on December 31 turns 2 the very next day in counting age. That's exactly why Korea needed to standardize on international age.
Your zodiac animal doesn't change on January 1
The zodiac animal people commonly use follows the calendar and changes on January 1, but the zodiac animal used in Saju follows Ipchun. Ipchun falls around February 3–5 each year.
So if you were born in January or early February, you have two zodiac animals. This calculator shows you both. It's not about which one is right, but which standard you're speaking by.
Day pillar — the two characters of your birth day
Of the eight Saju characters, the two for the day you were born are called your day pillar. It's seen as the pillar that describes you most closely. Because the sixty Gapja cycle advances one pair per day, the same day pillar comes around every 60 days.
Explanations for each of the 60 day pillars are collected in All 60 day pillars. If you're curious about all eight characters, head to the Manseryeok calculator.
How it's calculated
Dates are calculated in Korea Standard Time (KST), and the lunar conversion was round-trip verified across 55,002 days from 1900 to 2050. We don't ask for your birth time — it isn't needed for calculating age, and if you're curious about your Saju hour pillar, use the Manseryeok calculator.
FAQ
What's the difference between international age and year-based age?
International age (man nai) counts the day you're born as age 0 and adds a year each time your birthday passes; it has been Korea's default way of calculating age since June 2023. Year-based age (yeon nai) is the current year minus your birth year, regardless of your birthday, and is used in some laws such as the Military Service Act and the Juvenile Protection Act. Korean counting age (seneun nai) is a customary method in which you start at age 1 at birth and add a year every time the year changes.
I was born in January and I'm confused about my zodiac animal
In Saju, the year changes at Ipchun (立春, Start of Spring). Ipchun falls between February 3 and 5 each year, so if you were born in January or early February, you take the previous year's zodiac animal. For example, if you are born before 10:46 a.m. on February 4, 2027, you are a Horse of 2026, not a Sheep of 2027. The zodiac animal commonly used with the calendar, on the other hand, changes on January 1.
What is a day pillar?
It's the two characters attached to the day you were born. Of the eight Saju characters, it's seen as the pillar that describes you most closely. Because the sixty Gapja cycle advances one pair per day, the same day pillar comes around every 60 days.
How are the days I've lived counted?
Your birth date counts as day 0, and we count the difference in days up to today. Many people celebrate milestone anniversaries like 100, 1,000 and 10,000 days; 10,000 days comes about 27 years and 4 months after birth.