What Is Saju? A Beginner’s Guide to the Korean Four Pillars

Saju (사주, 四柱) is the Korean name for a system that turns the moment of your birth into a chart of eight characters. The word means “four pillars”: one pillar each for the year, month, day and hour you were born. Koreans often say the full name, saju palja (사주팔자, 四柱八字), “four pillars, eight characters”, and use it the way English speakers use “destiny”.

Four pillars, eight characters

Each pillar is a pair of characters stacked on top of each other. The top one is a heavenly stem (천간, 天干, cheongan) and the bottom one is an earthly branch (지지, 地支, jiji). There are ten stems and twelve branches, and they combine into a repeating cycle of sixty pairs.

Jungkook’s chart, for example, starts with the year pillar 丁丑, the month pillar 戊申 and the day pillar 丙午. Add the hour pillar and you have eight characters. That is the whole chart.

The five elements

Every one of those characters belongs to one of five elements: wood, fire, earth, metal or water. A reading starts by counting them. A chart heavy in fire and missing water is read very differently from a balanced one. The elements also relate to each other: each one feeds another and restrains another, and most of Saju is the study of those relationships. Our guide to the five elements covers this in detail.

The day master

Out of the eight characters, one stands for you: the stem of your day pillar, called the day master (일간, 日干, ilgan). Everything else in the chart is read in relation to it. Jungkook’s day master is 丙, Yang Fire, pictured as the sun. There are ten possible day masters, described in our day master guide.

Where it comes from

The system originated in China, where it is known as BaZi (“eight characters”), and took its present day-master-centred form around the Song dynasty. It spread across East Asia and has been practised in Korea for centuries under the names Saju and Myeongnihak (명리학, 命理學, “the study of fate”). The calendar behind it is solar: Saju months begin at fixed points in the sun’s yearly path, called solar terms, rather than on the first of a calendar month.

What a reading looks at

Your day master: its element and whether it is Yin or Yang.
The balance of elements: which are plentiful and which are missing.
Relationships between characters: harmonies, combinations and clashes inside the chart.
Compatibility: how two people’s charts interact, known as gunghap.

A full professional reading goes further, into ten-year luck cycles (대운, 大運, daeun) and yearly forecasts. This site keeps to the foundations: the pillars, the elements and compatibility.