The BaZi Conception Pillar: Four Auxiliary Pillars Beyond the Four Pillars
The Four Pillars capture the year, month, day and hour of the moment of birth. Some schools felt that was not enough, so they reached back to conception (the Conception Pillar and the Conception Breath), or derived a "Life Palace" and "Body Palace" from the birth month and hour. These are the auxiliary pillars: recorded in the classics and valued by some, but not the main actors in Zi Ping BaZi.
The four auxiliary pillars at a glance
| Auxiliary pillar | How it is calculated | What it was meant to show | Needs birth hour |
|---|---|---|---|
| Conception Pillar (胎元 tai yuan) | Month stem one step forward, month branch three steps forward | The qi of the month of conception; the inborn foundation | No |
| Conception Breath (胎息 tai xi) | The stem that combines with the day stem, the branch that combines with the day branch | The qi of the day of conception | No |
| Life Palace (命宮 ming gong) | Month number plus hour number, taken from 14 or 26; stem by the Five Tigers rule | The palace of life, a second look at the keynote of a life | Yes |
| Body Palace (身宮 shen gong) | Month number plus hour number (hours counted from Zi), minus 12 if over 12 | The palace of the body, usually read against the Life Palace | Yes |
How we counted: our engine cast one chart for every day from 1960 to 2005, with the birth hour drawn by a fixed-seed random sample, 16,802 charts in all. The Zi Wei Life Palace comes from this site's Zi Wei Dou Shu chart engine.
The Conception Pillar: counting back nine months
The calculation is simple: move the month pillar's stem one step forward and its branch three steps forward. A Jia-Zi month pillar gives a Yi-Mao Conception Pillar. Why three steps? Because in the sixty-pair cycle of month pillars, one stem and three branches forward is exactly the same as going back nine months, which is roughly the month of conception. In our sample, the Conception Pillar matches the month pillar of the day 274 days before birth in 94.2% of charts; most of the rest are early or late births, or dates right on a solar-term boundary.
The Conception Pillar was used to look at what a person is born with. If its element is favorable, it is often read as a good foundation and an easy pregnancy; if it clashes with the month or day pillar, as a pull between what one is born with and what life brings later. Readings like these belong to a minority of schools, and our engine does not include the Conception Pillar in strength or favorable elements.
The Conception Breath: the day pillar's combinations
The Conception Breath takes the stem that combines with the day stem (Jia-Ji, Yi-Geng, Bing-Xin, Ding-Ren, Wu-Gui) and the branch that combines with the day branch (Zi-Chou, Yin-Hai, Mao-Xu, Chen-You, Si-Shen, Wu-Wei). A Jia-Zi day pillar gives a Ji-Chou Conception Breath. It is used even less than the Conception Pillar, mostly by schools that focus on inborn qualities.
The four auxiliary pillars of one chart
Born March 12, 1985, You hour (5–7 p.m.)
- Conception Pillar: the month pillar is Ji-Mao. Move the stem Ji one step forward and the branch Mao three steps forward to get Geng-Wu (Roadside Earth). Counting back nine months lands on the month pillar of roughly June 1984, which is exactly this.
- Conception Breath: the day pillar is Geng-Xu. Geng combines with Yi and Xu combines with Mao, giving Yi-Mao (Great Stream Water).
- Life Palace: the Mao month is month 2, and the You hour, counting from Yin, is hour 8. They add up to 10; 14 minus that is 4, which is Si. The year stem Yi supplies the stem by the Five Tigers rule, so the Life Palace is Xin-Si. This date falls before the Spring Equinox, so the mid-month school counts it as the previous month and gets Ren-Wu instead.
- Body Palace: the Mao month is month 2, and the You hour, counting from Zi, is hour 10. They add up to 12, which is Ji-Chou.
Find your Conception Pillar, Conception Breath, Life Palace and Body Palace
Enter your date and hour of birth to get all four auxiliary pillars and their Nayin at once. The Life Palace is shown under both the solar-term and mid-month schools, with the Zi Wei Life Palace alongside for comparison. Everything is calculated in your browser; nothing is uploaded.
Uses your Gregorian birth date, with the day changing at 11 p.m. The Conception Pillar and Conception Breath need no birth hour; the Life Palace and Body Palace do.
Three common misunderstandings
The Conception Pillar gives the exact time of conception.
It is a stem-branch pair derived from the month pillar, roughly the month pillar nine months before birth. Real pregnancies vary in length, and in our sample 5.8% of charts still do not line up. It is a symbol, not a medical conception date.
The BaZi Life Palace and the Zi Wei Life Palace are the same thing.
They are calculated differently: the BaZi Life Palace uses solar-term months, while Zi Wei Dou Shu uses lunar months and a different formula. In our sample they fall on the same branch in only 3.9% of charts.
Auxiliary pillars are more accurate or go deeper than the four pillars.
They are a supplement used by a minority of schools; mainstream Zi Ping still reads the four pillars. Drawing conclusions from the Life Palace or Conception Pillar alone easily goes wrong.
Read on
A straight word: auxiliary pillars are a supplement, not the main event
The Conception Pillar, the Life Palace and the rest are recorded in the classical texts and some schools rely on them, but mainstream Zi Ping reads a person from the four pillars themselves. We calculate the auxiliary pillars and explain the methods and where schools disagree, but we do not feed them into strength or favorable elements. If someone makes a big claim from the Life Palace or the Conception Pillar alone, it is fair to ask what the four pillars say. Everything on this site is for reference and entertainment.
After the auxiliary pillars, back to the four pillars
The in-depth reading works out strength and favorable elements from the four pillars, then covers personality, career, relationships and luck pillars: the main basis for understanding yourself.
Conception Pillar and Life Palace FAQ
How do you calculate the Conception Pillar in BaZi?
Move the month pillar's stem one step forward and its branch three steps forward. A Jia-Zi month pillar gives Yi-Mao; a Bing-Yin month pillar gives Ding-Si.
What does the Conception Pillar represent?
Roughly the month pillar nine months before birth. Classical methods used it to look at the qi of the time of conception and the foundation a person is born with. It is a supplementary tool used by a minority of schools.
What is the Conception Breath?
The stem-branch pair formed by the stem that combines with the day stem and the branch that combines with the day branch. A Jia-Zi day pillar has a Ji-Chou Conception Breath, said to reflect the qi of the day of conception.
Does a BaZi reading need the Conception Pillar or Life Palace?
Not necessarily. Mainstream Zi Ping reads the four pillars, and auxiliary pillars are mostly for reference. We calculate them but leave them out of strength and favorable elements.