Eight Mansions Feng Shui Guide: Gua Numbers and Directions

Answer First

Definition: The Eight Mansions (Ba Zhai) system assigns every person one of eight Gua numbers—derived from birth year and gender—that groups them into East or West Life groups, each with four favorable and four unfavorable compass directions. Why: Practitioners use these Gua-number-to-direction mappings to orient beds, desks, and front doors in ways the tradition associates with well-being, relationships, and opportunity. Example: A man born in 1984 receives Gua number 1 (Kan, East Life group); his most favorable direction, Sheng Qi, points southeast, so a practitioner might suggest sleeping with the head of the bed toward that bearing.

Key Facts

This Eight Mansions Feng Shui guide keeps documented facts separate from interpretive tradition.

The Eight Mansions Feng Shui guide tradition rests on a small set of repeatable inputs. Understanding those inputs—and where they sit in the broader landscape of feng shui—helps separate what the method actually encodes from what individual practitioners or software tools later add on top. This matters because popular summaries often present as settled fact what the source texts treat as one interpretive tradition among several.

What the Method Uses

The core calculation needs only two pieces of personal data: birth year, interpreted by the Chinese lunar calendar convention, and gender. From those it derives a Gua number from 1 through 9, skipping 5, which is remapped to 2 for males and 8 for females. That Gua number then maps onto one of the eight trigrams of the Bagua and determines whether the person belongs to the East Life group—Gua numbers 1, 3, 4, and 9—or the West Life group—Gua numbers 2, 6, 7, and 8.

Each Gua number comes with a fixed look-up table of four auspicious and four inauspicious directions, each labeled with a classical Chinese name. On the favorable side: Sheng Qi (Generating Breath), Tian Yi (Heavenly Doctor), Yan Nian (Longevity), and Fu Wei (Stability). On the unfavorable side: Huo Hai (Calamity), Wu Gui (Five Ghosts), Liu Sha (Six Killings), and Jue Ming (Severed Fate). The order and exact compass bearings differ by Gua number, but the eight labels are the same for everyone. The labels sound dramatic to a modern English-speaking reader. They reflect a classical cosmology where directional energies were understood to shape human fortune in tangible ways; contemporary practitioners often treat them as a spectrum of caution rather than literal prophecy, a subtlety that popular summaries frequently omit.

Where Eight Mansions Sits Among Feng Shui Schools

Feng shui is not one system. Scholars broadly distinguish the Form School (Xing Shi), which reads land contours, watercourses, and building shapes, from the Compass School (Li Qi), which uses the luopan compass and time-based calculations. Mak and So (2009, p. 56) document this division as foundational. Eight Mansions is a Compass School method—it relies on direction and personal birth data rather than landscape observation—but it uses a simpler compass ring than Flying Star (Xuan Kong Fei Xing), another Compass School method that layers in twenty-year periods and annual star movements.

For a fuller comparison of how these two major school families differ in practice, see the discussion of Form School and Compass School methods compared side by side. Because Eight Mansions is personal—your Gua number stays with you for life—and comparatively straightforward to teach, it has become one of the most widely distributed feng shui methods in popular books, mobile apps, and online calculators. For a broader orientation to where Eight Mansions fits among other well-known systems alongside Flying Star, BTB, and classical Form School approaches, the complete guide to feng shui schools and their limits maps the full landscape.

What the Classical Texts Do Not Claim

Classical Eight Mansions texts describe directional affinities. They are modest in scope: they assign directions to Gua categories, not life outcomes to individuals. Mak and So (2009) note that the basics of Eight Mansions theory were originally presented as a classification system for aligning human dwellings with cosmological patterns, not as a predictive technology in the modern sense. The predictive layers—specific health outcomes, financial windfalls, relationship guarantees—are mostly modern additions, sometimes from well-meaning popularizers, sometimes from app developers who need to display a concrete fortune to keep users engaged.

Bruun (2008), surveying feng shui research across multiple traditions in his chapter on research context, cautions against treating any feng shui method as settled empirical science. The research tradition is rich and culturally significant, but its knowledge claims belong to a different epistemological framework than controlled experimental prediction. Directional affinities expressed in the Eight Mansions Feng Shui guide tradition are culturally meaningful interpretive tools; they have not been validated as reliable forecasts through independent controlled research.

Expert Explanation

A careful Eight Mansions Feng Shui guide states which rules are historical, conventional, or uncertain.

Step One: Calculating the Gua Number

The calculation itself is arithmetic, but the conventions around it are cultural. Here is the standard formula taught in most Eight Mansions Feng Shui guide materials, presented with enough detail that you can replicate it by hand and audit any calculator you encounter.

For males: Add the last two digits of the birth year. If the sum is 10 or greater, add those digits together until a single digit remains. Subtract that digit from 10. The result is the Gua number. If the result is 5, it becomes 2.

For females: Add the last two digits of the birth year. Reduce to a single digit as above. Add 5. If the result is 10 or greater, reduce again. The result is the Gua number. If the result is 5, it becomes 8.

Worked example—male born in 1984: Last two digits are 8 and 4. 8 plus 4 equals 12. 1 plus 2 equals 3. 10 minus 3 equals 7. Gua number: 7, corresponding to the Dui trigram and the West Life group.

Worked example—female born in 1992: Last two digits are 9 and 2. 9 plus 2 equals 11. 1 plus 1 equals 2. 2 plus 5 equals 7. Gua number: 7, corresponding to the Dui trigram and the West Life group. Note that these two people, born eight years apart and of different genders, happen to arrive at the same Gua number—the math produces overlap.

For births from the year 2000 onward: The formula shifts. For males born in 2000 or later, subtract the reduced single digit from 9 instead of 10 (and remap 5 to 2). For females born in 2000 or later, add 6 instead of 5 before the final reduction (and remap 5 to 8). This adjustment is recognized in most current teaching materials, but not all older calculators have been updated.

The Lunar Year Boundary: Where Most Calculators Diverge

The single most common source of disagreement across Eight Mansions calculators is the treatment of the Chinese lunar new year boundary. The formula uses the Chinese calendar year, not the Gregorian January-to-December year. Someone born on 28 January 1985 might still fall in the Year of the Rat’s predecessor, depending on whether the lunar new year for that cycle fell in early or late February.

No universal agreement exists among software implementations about which lunar-year table to use. Some calculators hard-code a simplified rule—for example, treating 4 February as the cutoff every year, which is actually the Li Chun solar term, a related but distinct concept from the lunar new year. Others query a lookup table. A few ignore the issue entirely and use the Gregorian year. The practical consequence: the same birth date can yield different Gua numbers depending on which tool you use, and the effect is most pronounced for January and February births. A person born on 1 February 1990 might get Gua 8 from one calculator and Gua 7 from another—not because one is “wrong” in a simple sense, but because they encode different conventions about which Chinese year that date belongs to.

Bruun (2008, chapter 4) documents that Compass School traditions have long exhibited internal variation in how time boundaries are treated, and the Gua-number calculation is one practical manifestation of that broader interpretive diversity. It is a feature of the tradition’s history, not a bug in its software implementations.

The Gua-5 Remapping

The Lo Shu magic square that underpins Eight Mansions has nine cells arranged in a three-by-three grid, but only eight Gua numbers are actually used: 1, 2, 3, 4, 6, 7, 8, and 9. When the formula yields 5—the center cell of the square—the tradition remaps it. Males with a raw result of 5 receive Gua 2 (Kun, Southwest), and females with a raw result of 5 receive Gua 8 (Gen, Northeast). This remapping is nearly universal across Eight Mansions schools, but it is significant because it means males and females with otherwise identical birth-year arithmetic can land in different trigram assignments at this boundary case.

The Eight Trigrams and Their Directions

Each Gua number corresponds to a trigram from the Bagua, and each trigram has a natural compass direction. Understanding the trigrams themselves—their names, images, and cultural associations—adds depth to why a particular direction is considered favorable or unfavorable. For a fuller introduction to the eight trigrams, their symbolic meanings, and how they appear across different feng shui systems, see the article on Eight Trigrams meaning, names, and uses.

Gua	Trigram	Chinese	Element	Direction	Life Group
1	Kan	坎	Water	North	East
2	Kun	坤	Earth	Southwest	West
3	Zhen	震	Wood	East	East
4	Xun	巽	Wood	Southeast	East
6	Qian	乾	Metal	Northwest	West
7	Dui	兌	Metal	West	West
8	Gen	艮	Earth	Northeast	West
9	Li	離	Fire	South	East

The Four Auspicious Directions, Ranked

For any Gua number, the four favorable directions appear in a fixed order of priority. The classical naming reflects a cosmology in which each direction carries a distinct quality of qi, and practitioners rank Sheng Qi first because it is understood to carry the most generative energy.

Sheng Qi (Generating Breath): The direction associated with vitality, reputation, and advancement. Practitioners often prioritize this bearing for the front door and the bedhead because it is considered the most active and outward-facing of the favorable four.
Tian Yi (Heavenly Doctor): Linked to health and recovery. Some consultants recommend this direction for the bed or a home office where someone recovering from illness or managing a chronic condition spends extended time.
Yan Nian (Longevity): Associated with harmonious relationships and marital stability. Commonly suggested for the bedroom of a couple or the dining table where family members gather. The character Yan carries the sense of something extended or prolonged.
Fu Wei (Stability): A milder favorable direction, linked to calm and personal equilibrium. Often recommended for a study desk, meditation corner, or any space where quiet focus matters more than outward activity.

The Four Inauspicious Directions, Ranked from Least to Most Severe

Huo Hai (Calamity): Misfortune and obstacles that are disruptive but not catastrophic. Practitioners suggest avoiding this direction for the front door and bed.
Wu Gui (Five Ghosts): Conflict, gossip, and fire-related accidents. Often flagged for kitchen and stove placement because of the fire association. The name refers to five types of spectral influence in Chinese folk tradition.
Liu Sha (Six Killings): Legal problems, illness, and betrayal. Some consultants recommend keeping this sector quiet or using it for storage rather than for occupied rooms.
Jue Ming (Severed Fate): The most serious unfavorable direction, associated with total loss, severe health threats, and irreversible misfortune. Classical advice says never to face this direction while sleeping, working, or eating. The name literally suggests a cutting off of destiny.

Three More Ways Calculators Disagree

Beyond the lunar-year boundary issue, calculators diverge on at least three additional points that affect the directions they recommend.

Compass-reference convention. Some tools report directions relative to magnetic north; others use true north, which differs by the local magnetic declination—anywhere from a few degrees to over fifteen degrees depending on your location. The classical luopan compass references magnetic south, which is magnetic north flipped 180 degrees, but smartphone apps use the device magnetometer, which reports magnetic north with calibration that varies by device and environment. A direction labeled south by one tool might be off by several degrees from another—potentially enough to shift a doorway from one 45-degree sector to the next if it sits near a boundary.

Sector width and boundary placement. The eight directions each occupy a 45-degree arc of the compass. South, for example, spans 157.5 degrees to 202.5 degrees in the simplest model. But where exactly those boundaries fall depends on whether the tool centers each sector on the cardinal point—0 degrees, 45 degrees, 90 degrees, and so on—or uses a different offset convention. Some traditional luopan rings subdivide each 45-degree sector into three 15-degree segments, and the inner logic of those subdivisions does not always align neatly with the simplified eight-sector model used by most consumer-facing apps.

Hybrid overlays with other methods. Some calculators blend Eight Mansions directions with Flying Star period charts, annual star movements, or the eight life-area aspirations of the BTB Bagua, producing hybrid recommendations that are not part of classical Eight Mansions at all. A user who compares two tools—one running pure Eight Mansions and another running a hybrid—may see contradictory advice and conclude that one tool is broken, when in fact they are running different systems under the same label. Chien and Wu (2024), in their comparative analysis of Form and Compass schools, confirm that the Compass School encompasses multiple interpretive sub-traditions that, while historically related, are not interchangeable. Users who treat them as such run into the discrepancies described here.

Decision Framework

Use the Eight Mansions Feng Shui guide as a review aid, not as authority for a consequential decision.

When Eight Mansions Is a Reasonable Fit

Eight Mansions works best when your question is straightforward and personal: given my birth year, which compass directions does this tradition associate with favorable or unfavorable energy for me? The method is static—your Gua number and directions do not change year to year—so it suits someone who wants a one-time directional map rather than an annual consultation.

The method requires no site visit, no construction data, and no floor-plan measurements beyond the ability to identify compass bearings from the center of a room or home. For renters and apartment dwellers who is unable to alter the building shell, a direction-based method is more actionable than a form-based approach that reads landscape contours or recommends structural changes. The feng shui for renters checklist covers additional space adjustments—furniture placement, color, materials—that complement any direction-based approach without requiring renovation.

Eight Mansions also pairs naturally with the concept of the command position, the widely recommended practice of placing key furniture so you can see the door without being directly in line with it. For more on how the command position works and where its limits lie, see the article on the feng shui command position, its meaning, and its practical bounds. When the command position conflicts with your Gua number’s best direction, the tradition offers no single resolution rule; most practitioners negotiate a compromise based on which factor—visibility of the door or alignment with Sheng Qi—feels more pressing for the occupant’s current circumstances.

When to Be Cautious

January or February births. If you were born in either of these months, run your birth date through at least two calculators that explicitly state they use the Chinese lunar calendar. Note the lunar new year date each one assumes. If the Gua numbers disagree, look up the actual lunar new year for your birth year from a published almanac or a reputable astronomical source, and choose the Gua number that matches. Do not assume the first calculator you try is correct by default.

Apartments with angled walls or irregular floor plans. The eight-direction model assumes you can identify cardinal directions from the center of the home. In a building where walls run at odd angles, or where a studio apartment has no distinct center, sector boundaries blur. Some practitioners apply the method at room level—orient a single chair rather than the whole apartment—which reduces precision requirements but also departs from the classical house-level method. The simplification may be pragmatically useful; it is not, however, what the classical texts describe.

Shared spaces with mixed Life groups. A couple with different Gua numbers—one East Life, one West Life—is unable to both face their personal Sheng Qi directions from the same bed. The tradition offers compromise conventions: prioritize the primary income earner, or use the direction of the person with the more pressing health or relationship concern. These are social conventions layered on top of the method, not deductions from it. Acknowledge that you are making a pragmatic choice when you select one person’s direction over another’s.

When the question is about timing, not direction. Eight Mansions is static. If your question is whether 2027 is a good year to move, start a business, or renovate, you are asking a Flying Star or BaZi question, not an Eight Mansions question. For time-sensitive analysis, the Flying Star Feng Shui guide covering periods and annual star directions explains how period charts and annual movements work within that separate compass-based tradition.

A Practical Self-Checklist

Use this checklist to decide whether Eight Mansions applies to your situation and, if so, to apply it with reasonable care:

I have my birth year and know whether I was born before or after the Chinese lunar new year for that year.
I have calculated my Gua number using the standard formula and have cross-checked it across at least two calculators that state their lunar-year convention.
I have a compass or smartphone app that can identify the cardinal directions from the center of the room or home.
I can identify which 45-degree sector each wall, door, and major furniture piece faces relative to the center point.
I have looked up my four favorable and four unfavorable directions from a printed or published table—not solely from a calculator that mixes methods without disclosure.
I understand that the direction labels describe traditional energetic affinities and have not been established as reliable scientific forecasts for health, wealth, or relationship outcomes.
If I share the space with someone of a different Life group, I have decided which compromise rule to apply and have acknowledged that it is a social choice, not a rule internal to Eight Mansions theory.
I am not confusing Eight Mansions with Flying Star, BTB Bagua, or BaZi; if my question involves a specific year or time period, I have checked whether a time-based feng shui method is more appropriate.

Gua Number Quick-Reference Direction Table

Gua	Trigram	Life Group	Sheng Qi (Best)	Tian Yi (Health)	Yan Nian (Relationships)	Fu Wei (Stability)
1	Kan	East	SE	E	S	N
2	Kun	West	NE	W	NW	SW
3	Zhen	East	S	N	SE	E
4	Xun	East	N	S	E	SE
6	Qian	West	W	NE	SW	NW
7	Dui	West	NW	SW	NE	W
8	Gen	West	SW	NW	W	NE
9	Li	East	E	SE	N	S

The four unfavorable directions for each Gua number are the four compass points not listed in the row above. Their rank order—Huo Hai through Jue Ming—can be derived from classical directional tables available in standard references such as Mak and So (2009). If you print or save this table, note which compass-reference convention the directions assume and whether your compass or phone app uses the same convention.

Key Takeaways

The most useful Eight Mansions Feng Shui guide preserves context, assumptions, and personal agency.

The Eight Mansions Feng Shui guide system reduces to a compact input set—birth year per the lunar calendar plus gender—and produces a fixed directional map that stays with you for life. The arithmetic is simple enough to check by hand, which is the most reliable way to audit any calculator you encounter.
The single most consequential variable in Gua number calculation is whether the tool uses the Chinese lunar new year or an approximation. For January and February births, this choice alone can change your Gua number, your Life group, and therefore every directional recommendation that follows.
The eight direction labels—Sheng Qi, Tian Yi, Yan Nian, Fu Wei, Huo Hai, Wu Gui, Liu Sha, and Jue Ming—belong to a classical Chinese cosmological vocabulary. They express traditional directional affinities. They are not scientific predictions of health, wealth, or relationship outcomes, and no controlled study has established them as reliable forecasts in the empirical sense.
Contemporary scholarship by Bruun (2008), Mak and So (2009), and Chien and Wu (2024) documents that the Compass School tradition has always contained multiple interpretive branches. Eight Mansions is one branch, not the whole tree, and internal variation—including in how digital calculators implement it—reflects that interpretive heritage.
Calculator disagreements are most common around four points: lunar-year boundaries for January and February births, compass-reference conventions—magnetic versus true north—sector-boundary placement within the 45-degree arcs, and undisclosed hybrid overlays with Flying Star or BTB Bagua elements. When two tools disagree, the cause is almost always traceable to a specific, identifiable input convention rather than to flawed arithmetic.
The method is most appropriate for static, personal-direction questions—which way should I orient my bed or desk?—and less appropriate for time-sensitive questions or multi-person households where directional compromises must be negotiated through social conventions external to the method.
Predictive or outcome-oriented claims that go beyond directional affinity—specific financial returns, promised health improvements, precise relationship outcomes—are culturally meaningful to many practitioners but belong to modern popularization, not to the classical Eight Mansions texts. Readers who approach the Eight Mansions Feng Shui guide tradition as a cultural and reflective practice, rather than as a source of promised predictions, are better positioned to engage with it honestly and without over-claiming.
The broader feng shui field includes other schools with different strengths. For a parallel exploration of how uncertain inputs affect another tradition, see the discussion of birth time documented limits in BaZi and its practical implications, which addresses analogous input-variability questions in the Four Pillars system.

FAQ

These questions clarify how a Eight Mansions Feng Shui guide can remain practical without promising prediction.

Q: Can my Gua number change over time? A: No. In classical Eight Mansions, your Gua number is fixed at birth and does not change with age, calendar year, or relocation. Some modern hybrid tools layer annual Flying Star influences on top, which can create an impression of change, but the underlying Gua number and its associated directions remain constant.

Q: What if my partner and I belong to different Life groups? A: This is one of the most common practical dilemmas. The tradition offers several compromise conventions—prioritize the primary income earner, the person with a specific health concern, or the direction of the door rather than the bed—but none is a universal rule. The choice is a pragmatic social decision, not a deduction from Eight Mansions theory.

Q: Why do different Eight Mansions calculators give me different Gua numbers? A: The most frequent cause is disagreement about the lunar-year cutoff date for your birth year. If you were born in January or February, one calculator may place you in the previous Chinese year while another places you in the next. Check whether each tool publishes its lunar-year convention, and cross-reference with a published almanac for your specific birth year.

Q: Do I need a professional luopan compass, or can I use my phone? A: A smartphone compass is sufficient for an initial Eight Mansions reading, provided you calibrate it first and understand its margin of error, typically within five degrees. The eight sectors are each forty-five degrees wide, so moderate compass error is unlikely to cross a sector boundary. For precise door-alignment work, a physical luopan or surveyor’s compass reduces documented limits.

Q: Is Eight Mansions compatible with the Bagua map I see in other feng shui guides? A: Partially, but they are different systems. Eight Mansions uses the eight trigrams as personal directional affinities, while the popular BTB Bagua map overlays eight life-area aspirations onto a fixed floor-plan grid. For more on that distinction, see the article on the Feng Shui Bagua map, its areas, and its schools. Practitioners sometimes blend the two, but classical Eight Mansions does not use the BTB life-area overlay.

Q: What if I do not know my exact birth time—does that affect my Gua number? A: No. Eight Mansions needs only birth year and gender, not birth hour. If your question involves birth time, you are likely thinking of BaZi, the Four Pillars of Destiny, which is a different system. For issues around missing or uncertain birth data in that context, see the article on birth time documented limits in BaZi and its practical limits.

Sources

Mak, M. Y., & So, A. T. (2009). An Assessment into the Basics of Eight Mansions Feng Shui Theory. In Scientific Feng Shui for the Built Environment (pp. 55–70). City University of Hong Kong Press. https://doi.org/10.1515/9789629374846-008
Bruun, O. (2008). Feng Shui Research. In An Introduction to Feng Shui (pp. 67–90). Cambridge University Press. https://doi.org/10.1017/CBO9780511800931.004
Bruun, O. (2008). Cosmological Principles, Schools of Interpretation and the Feng Shui Compass. In An Introduction to Feng Shui (pp. 91–118). Cambridge University Press. https://doi.org/10.1017/CBO9780511800931.005
Chien, S.-C., & Wu, C.-H. (2024). Comparative Analysis of Form and Compass Schools in Feng Shui Architecture. Nakhara: Journal of Environmental Design and Planning, 23(4), 1–20. https://doi.org/10.54028/nj202423420

Keyword-specific review notes

Check 1 for this Eight Mansions Feng Shui guide is to preserve the source, convention, and uncertainty behind the conclusion.