What Is Bát Trạch?
Bát Trạch (literally "eight mansions" or "eight positions") is one of the oldest and most widely used feng shui schools, grounded in the Bagua (Eight Trigrams) principle from the I Ching. This school holds that each person, based on birth year and gender, has a unique number called the Kua number (Cung Phi). This number determines whether a person belongs to the East Life Group or the West Life Group, which in turn indicates which house direction, desk orientation, or bed placement is auspicious or inauspicious for that specific individual.
What sets Bát Trạch apart is its personalized approach: no single direction is universally good for everyone, favorability depends on whether that direction matches the homeowner's Kua number.
How to Calculate the Kua Number
The most common formula uses the last two digits of a person's birth year (Gregorian calendar), summed and reduced to a single digit, then applied differently for men and women, and differently again depending on whether someone was born before or after 2000:
- Men born before 2000: subtract the reduced sum from 10 (if the result is 10, use 1).
- Men born in 2000 or later: subtract the reduced sum from 9 (if the result is 0, use 9).
- Women born before 2000: add 5 to the reduced sum (reduce further if it's two digits).
- Women born in 2000 or later: add 6 to the reduced sum (reduce further if it's two digits).
One important note: if the calculated Kua number comes to 5, tradition substitutes number 2 (Kun) for men and number 8 (Gen) for women, since 5 has no fixed Bagua position of its own.
Because different feng shui schools use slight calculation variants (such as using the lunar year instead of the Gregorian one, or basing it on the date of Lichun/Start of Spring), the most accurate and convenient approach is to use an online Kua number calculator for a consistent result.
East Life Group and West Life Group
Once the Kua number is known, people are sorted into two broad groups:
East Life Group (Kua 1, 3, 4, 9)
This group corresponds to the four trigrams Kan, Zhen, Xun, and Li, and favors directions belonging to the East Four Houses: North, South, East, and Southeast.
West Life Group (Kua 2, 5, 6, 7, 8)
This group corresponds to the four trigrams Kun, Qian, Dui, and Gen, favoring directions in the West Four Houses: West, Northwest, Southwest, and Northeast.
The basic principle of Bát Trạch is that a person should prioritize orienting their front door, bedroom, and desk toward directions within their own group to receive compatible energy.
The Four Auspicious and Four Inauspicious Directions
Within each life group, there's a further breakdown into four auspicious and four inauspicious directions, each tied to a different type of energy:
The four auspicious directions typically include: Sheng Qi (the best, tied to wealth and career advancement), Yan Nian (good for love and relationships), Tian Yi (good for health), and Fu Wei (good for stability and personal growth).
The four inauspicious directions include: Jue Ming, Wu Gui, Liu Sha, and Huo Hai, each associated with a different type of misfortune such as financial loss, illness, conflict, or accidents.
The exact compass position of these eight directions varies according to each person's Kua number, so no single diagram applies to everyone, which is why Bát Trạch is considered a highly individualized feng shui system.
Practical Application
In daily life, Bát Trạch is commonly applied to choosing a front door direction, bed placement (with the head pointing toward a favorable direction), desk orientation for work or study, and seating direction for important meetings or negotiations. That said, feng shui practitioners also note that Bát Trạch is just one of several schools (alongside Xuan Kong Flying Star, Form School, and others), so it should be combined with other practical factors of a living space, such as lighting, airflow, and convenience, for the best overall effect, rather than applying a single rule mechanically.
