Korean Zodiac Calculator — your animal sign, star sign and age from one birth date

How to use it

Pick your date of birth. If you know the hour you were born, choose it too — that adds the traditional two-hour branch, which is one of the four pillars used in Korean saju readings. Press the button and everything appears at once. You can copy a link or save the result as an image to compare with family and friends.

How the animal is calculated

animal index = (birth year − 4) mod 12, where 0 = Rat

The twelve-year cycle runs Rat, Ox, Tiger, Rabbit, Dragon, Snake, Horse, Goat, Monkey, Rooster, Dog, Pig. The offset of four looks arbitrary but is not: the cycle is anchored to the traditional sexagenary calendar, which does not line up with the Gregorian year zero. Take 1996 as an example. 1996 minus 4 is 1992, and 1992 divided by 12 leaves no remainder, so 1996 is a Rat year.

Each animal also carries a branch character from the twelve Earthly Branches, written above the animal in the result. These are the same characters used to name the hours, which is why the systems look so similar.

The lunar new year caveat, stated up front

This is the one thing worth knowing before you trust any zodiac calculator, including this one. Traditionally the animal year does not begin on January 1. It begins at the lunar new year, which drifts between late January and late February, and stricter saju practice starts it at 입춘 (ipchun), the solar term marking the start of spring around February 4.

This calculator uses the calendar year, because that is what Koreans use in everyday conversation and what people mean when they say "I am a Dragon". But if you were born in January or the first half of February, a traditional reckoning may put you under the previous animal. The tool flags this on screen rather than quietly picking one answer, because a zodiac tool that silently gets your animal wrong is worse than one that tells you where its edges are.

The twelve animals

The two-hour branches

Before clocks, the Korean day was divided into twelve blocks of two hours each, and each block took an animal name from the same cycle. The day starts with Jasi at 23:00, not at midnight, which is why the first block straddles two calendar days.

Western star sign ranges

Star signs come from the sun's position on your birth date, so unlike the animal cycle they change through the year. Boundary dates shift by a day between sources because the sun does not cross them at the same clock time every year; the ranges below are the conventional ones this tool uses.

Three things people get wrong

1. Thinking the Korean and Chinese zodiacs are different systems. They are the same cycle with the same year mapping, shared across the region. Naming and local custom differ; Vietnam alone swaps two animals.
2. Assuming the year starts on January 1. It does in casual use and in this tool, but not in traditional reckoning. Anyone born in January or early February should read the caveat above.
3. Treating the animal as an age. An animal repeats every twelve years, so knowing someone is a Tiger narrows their age to 1974, 1986, 1998, 2010 or 2022. Koreans use it alongside visible context, not on its own.