Four Pillars of Destiny (BaZi/Saju): A Beginner's Guide

Four Pillars of Destiny — BaZi in Chinese, Saju in Korean — is an East Asian fortune-telling system built entirely from your exact birth date and time. Here are the basic building blocks.

Four pillars, eight characters

A chart is built from four "pillars" — year, month, day, and hour — each made of two characters: a Heavenly Stem and an Earthly Branch. Four pillars of two characters each total eight characters, which is where the Chinese name BaZi ("eight characters") comes from.

The 10 Heavenly Stems

Ten Heavenly Stems cycle repeatedly through the calendar, each tied to one of the Five Elements in either a yin or yang form (for example, Yang Wood and Yin Wood are two different stems).

The 12 Earthly Branches

Twelve Earthly Branches are tied to the 12 zodiac animals and, separately, to specific two-hour windows of the day, which is why the hour pillar depends on knowing a precise birth time.

The Day Stem represents "self"

Within the eight characters, the Day Stem is traditionally treated as representing the person themselves — the core reference point that the rest of the chart's elements are interpreted against.

Why it is called "eight characters"

BaZi literally translates to "eight characters," referring to the two characters (a stem and a branch) in each of the four pillars. Saju, the Korean term, literally means "four pillars," describing the same eight-character structure from a slightly different angle.

How Saju, BaZi, and related practices differ across cultures

The underlying stem-and-branch theory is shared, but its cultural role differs: Saju is deeply woven into Korean New Year traditions and traditional matchmaking practices (where a "compatibility reading," or gunghap, compares two people's charts), while BaZi is more associated with Chinese business and feng shui consultations, and the practice is less commonly formalized in Japan.

Frequently Asked Questions

Do I need my exact birth time to get an accurate chart?

Yes. The hour pillar specifically requires a precise birth time; without it, a chart is usually built with only three pillars, which practitioners generally consider incomplete.

Is this the same as Western astrology?

No. The two are conceptually similar in using birth data to build a personality or fate framework, but Four Pillars is based on a lunisolar calendar stem-and-branch system, entirely unrelated to the positions of stars and planets used in Western astrology.