TL;DR: Saju (사주, "Four Pillars") is a Korean fortune-telling system based on the four pillars of the year, month, day, and hour of birth, sharing roots with Chinese Bazi but with its own identity and interpretive methods after centuries of localization. Today, Saju is still widely trusted by many Koreans, especially for marriage compatibility (gunghap, 궁합) and career direction; online forms are also popular, and according to David J. Kim's 2019 study, the readings people receive online are experienced as a kind of emotional experience, not merely information.
Saju (사주): Korean Four Pillars: Origins, Calculation and Application in Korean Life
What are the origins of Saju?
Saju (사주, Hanja: 四柱, meaning "Four Pillars") is a system of destiny reading based on the moment of birth, widely used by Koreans to this day. At its roots, Saju is not a purely Korean invention but derives from the Chinese art of Bazi (八字), a system using the eight characters of the Heavenly Stems and Earthly Branches to describe a moment of birth, shaped in astrological and calendrical works of the Tang dynasty (618–907). Along with currents of Confucian knowledge, yin-yang and the five elements, and Chinese calendrics, Bazi entered the Korean peninsula through centuries of cultural exchange, and was gradually localized into Saju.
The mathematical common ground is the system of ten Heavenly Stems (천간, Cheongan) and twelve Earthly Branches (지지, Jiji) used to set four pillars of stem and branch. The difference between the two traditions lies in the cultural layer built on top of that shared frame: the manner of interpretation, the terminology, and the social values each culture attaches to particular stem-branch combinations.
A summary table of the four pillars in a Saju chart, with the time each represents and the meaning assigned to it in reading.
| Pillar | Time | Meaning in reading |
|---|---|---|
| Year Pillar | Year of birth | Ancestral influence, family roots |
| Month Pillar | Month of birth by solar term | Environment of youth, career |
| Day Pillar | Day of birth | The day stem is the Day Master, representing the person whose chart is read |
| Hour Pillar | Hour of birth | Later life, children |
How has Saju developed through history?
Over centuries of practice in Korea, Saju absorbed local Confucian values, tied to the 24 solar terms of the agricultural calendar and the rhythms of traditional farming life. Under Joseon (1392–1897), a dynasty that made Confucianism the state ideology, consulting Saju became an indispensable part of life's weighty decisions, especially marriage. The matching of the two families' birth data before a wedding, called gunghap (궁합, "compatibility"), was once almost a requirement rather than an option, since marriage at that time was seen as a union of two lineages more than of two individuals.
In the course of localization, Koreans developed additional concepts and emphases of their own. For instance, the notion of "Gwanssal" (관살), the group of stars linked to power, office and control, carries a distinctive social weight in Korean Saju readings, clearly reflecting the Confucian view of hierarchy, career and family duty. Such differences lie not in the calculation but in how a particular society interprets and applies the same system of signs.
In the modern era, despite rapid industrialization and the strong influence of Christianity, Saju has by no means faded. The profession of Saju reading (its practitioners generally called palgeoja/사주팔자 or saju-cheolhak-gwan) remains widespread across Korean cities, from small stalls in back alleys to mobile apps and online reading services aimed at young people. This persistence is not unique to Saju: in Shamans, Nostalgias, and the IMF (2009), Laurel Kendall shows that Korean folk belief adapted to the market economy of the industrial age and even to the financial crisis of 1997, rather than disappearing. People still turn to such practices when economic life raises questions about fortune, work and money.
Why does online Saju reading still hold appeal?
According to David J. Kim's ethnographic research (2019) on saju palcha reading in Korea, both in person and on digital platforms, clients do not receive an online prediction as a dry piece of information but experience it as an emotion. The prediction evokes a feeling of being seen, comforted or warned, and that feeling accounts for much of the appeal of the online form.
This also fits the context Laurel Kendall describes in Shamans, Nostalgias, and the IMF (2009): when economic life is unsettled, the need to find an explanation for one's fortune does not diminish but simply shifts into new forms. With Saju, those new forms are mobile apps, websites and consultations conducted through a screen.
What are the core principles of Saju?
- Foundational principle: the moment a person is born marks a particular configuration of cosmic energy, a combination of the Heavenly Stems (10 elements: Giáp, Ất, Bính, Đinh, Mậu, Kỷ, Canh, Tân, Nhâm, Quý) with the Earthly Branches (12 zodiac animals: Tý, Sửu, Dần, Mão...), each element carrying the properties of the Five Elements (Wood, Fire, Earth, Metal, Water) and of Yin and Yang. The four moments of birth, year, month, day and hour, form four "Pillars" (기둥, gidung), each pillar made of one stem and one branch, eight characters in all (八字) describing the "energy map" of a life.
From these eight characters, the Saju reader identifies the "Day Master" (일간, ilgan, the Heavenly Stem of the Day Pillar) as the center of analysis: which element is strong, which is weak, how the elements generate or control one another across the chart as a whole. This is the core common ground with Chinese Bazi. But saying "identify the Day Master as the center" is only the opening step. The actual chain of reasoning in the discipline passes through four stations: measuring the strength or weakness of the Day Master, determining the chart's structure, choosing the useful god to balance it, and only then moving to interpretation. The four sections that follow walk through exactly that chain.
In Saju (사주), when is something favorable or unfavorable under a strong or weak self, and when does it become the useful god?
In Saju (사주), the month command determines the strength or weakness of the Day Master, and from that the chart's structure leans one way. The useful god of Saju (사주) is not fixed: when the self is strong, it is usually the element that restrains; when the self is weak, it is usually the element that supports. Saju (사주) becomes the useful god only when supporting or restraining, mediating, regulating temperature, or treating the ailment applies precisely to it. If the chart falls into a following structure, Saju (사주) can shift from unfavorable to favorable. For the full picture, see The useful god in Bazi and Strong self, weak self.
How is the chart structure named?
The chart structure (格局) is the mold of the chart, the overall type of configuration the eight characters produce. The structure is named after whichever god holds the month command and is revealed in the stems (appears among the Heavenly Stems). For example, if the month branch is Dần and the month stem, or the year stem or hour stem, reveals Giáp, the chart is classed in a structure related to Wood. If the month command is not revealed in the stems, the reader considers other stems and branches with more effective force to determine the structure.
Why determine the structure before choosing the useful god? Because the structure tells you what "game the chart is playing". A chart leaning toward the officer star (the restraining factor) raises different questions from a chart leaning toward the wealth star (the prosperity factor). The structure is not a decorative label; it sets the order of priority when weighing the useful god at the next step.
It should be said plainly: the chart structure is where the schools do not fully agree. Some schools take the month command as the absolute standard, others allow a structure to form from a combination of stems and branches outside the month command if that combination is stronger. This disagreement carries over into the choice of useful god, and that is why two teachers of different schools can reach two different conclusions on the same chart.
How is a Four Pillars chart calculated?
To set up a Saju chart, one needs the exact year, month, day and hour of birth in the local time of the place of birth, taking into account time zone differences and the timing of solar terms rather than the ordinary solar calendar. From those four data points, the reader consults stem-branch tables based on the 60-year and 60-day cycle of the Sixty Jiazi to determine:
- Year Pillar: the stem and branch of the year of birth, reflecting ancestral influence and family roots.
- Month Pillar: the stem and branch of the month of birth reckoned by solar terms, not the ordinary solar calendar, reflecting the environment of youth and career. The branch of this pillar is the month command mentioned above.
- Day Pillar: the stem and branch of the day of birth; the day stem is the "Day Master", representing the person whose chart is read.
- Hour Pillar: the stem and branch of the hour of birth, reflecting later life and children.
Once all eight characters are set, the reader goes on to calculate the "Major Luck" (대운, daeun), the successive ten-year periods of a life, each carrying its own stem-branch combination laid over the original chart, indicating how fortune rises and falls from one period to the next. Major Luck is the moving layer of time laid over the static layer of structure, and reading requires interpreting both layers at once.
Note that the method of setting the four pillars and the method of choosing the useful god are not a single rule on which every school agrees. Some schools emphasize the month command, others give greater weight to the stem-branch combination of the whole chart, and it is precisely this difference that lets two readers of different schools reach two different conclusions from the same chart.
How are Saju predictions and readings made?
The Saju reader (palgeoja) analyzes the balance of the Five Elements across the eight characters: which element is in excess, which is lacking, and from that reads character, health, a suitable career path, and the favorable and unfavorable periods of a life. The standard sequence is: set the four pillars, identify the Day Master, measure strength or weakness through the month command and the two remaining criteria, determine the structure, check whether the chart falls into a following structure, choose the useful god by one of the four methods already described, and only then read the specific layers of meaning.
One especially common application is gunghap (궁합), comparing two people's charts to see how well they match before marriage: whether the Five Elements of the two sides generate, harmonize with, or clash against each other. Although modern Korean society has become far more open, many families and young couples still turn to gunghap as a reference before moving toward marriage.
Beyond marriage, Saju is also consulted for other major decisions in life: choosing a profession, the timing of starting a business, examinations, even naming a newborn (the practice of jakmyeong, 작명) so as to supplement the elements missing from the chart. Because the choice of useful god has no unified order of priority among the schools, the result of a reading is a reference and depends on the school of the reader, not a single result on which every practitioner agrees.
Overview article on the topic: Saju (사주) is the Korean Four Pillars system, originating from Chinese Bazi, using the eight characters of the stems and branches to describe a moment of birth, and read through the sequence of measuring strength or weakness, determining the structure, choosing the useful god, and then reading the course of fortune.
