The numbers on a bagua map, and which map they belong to

Published 2026-08-24

If you have seen a bagua map with numbers written in the cells, the numbers came from one of two places, and telling them apart saves a lot of confusion. One set is the Lo Shu square, an arrangement of one to nine that has been attached to the eight directions for a very long time. The other set is the personal number that Eight Mansions works out from a birth date. They look similar on the page — small digits sitting in a grid — and they answer nothing like the same question.

The Lo Shu square: nine numbers in a fixed pattern

The Lo Shu is a three-by-three arrangement of one through nine where every row, every column and both diagonals add to fifteen:

4	9	2
3	5	7
8	1	6

That is the whole of it as arithmetic. What makes it a feng shui object is that the pattern gets laid over the eight directions with 1 at north and 9 at south, which fixes a number to each direction: 1 north, 8 northeast, 3 east, 4 southeast, 9 south, 2 southwest, 7 west, 6 northwest, and 5 in the middle with no direction of its own.

Those number-to-direction pairings are stable across the compass schools. Where you see a bagua diagram with a number in each of eight sectors and a 5 in the center, this is what you are looking at.

The center being 5 is not a detail you can ignore, and it is the reason personal numbers behave oddly, which is the next section.

The personal number: one digit per person, not per direction

In Eight Mansions each person has a single number from their birth year and sex. It is not read off the plan — it is worked out from the birth date, and it decides which four of the eight directions suit that person.

The two numbering systems share the same one-to-nine range and the same trigram associations, and that shared vocabulary is exactly why they get mixed up. But the Lo Shu number tells you which direction you are looking at. The personal number tells you who is looking.

There is one place the overlap becomes a real problem. The center of the Lo Shu is 5, and 5 has no trigram and no direction. When the arithmetic for a person’s number lands on 5, there is nothing for it to point at, so the tradition substitutes another number — and the substitution is not the same for men and women. What gets substituted, and why the answer differs by sex when nothing else in the calculation does, is worked through in the number that gets substituted.

The practical consequence: a personal number is never reported as 5. If a calculator hands you a 5, it has skipped the substitution step.

The other bagua map has no numbers of its own

The three-door grid — the one where the front door decides which way the grid faces, from Black Sect Tantric Buddhism — carries names, not numbers. Wealth, Fame, Love, Family, Health, Children, Knowledge, Career, Helpful People. Nine cells, nine names.

Numbers do sometimes get printed on three-door diagrams anyway, borrowed from the Lo Shu because the grid is also three by three. That borrowing does not survive contact with the mechanics. In the three-door system the bottom row is wherever the front door is, so a cell’s position on the plan changes with the building’s entrance. In the Lo Shu the numbers are welded to compass directions and do not move. Putting Lo Shu numbers on a three-door grid asserts that a cell is both anchored to your door and anchored to north, and it cannot be both.

So if a diagram shows you cell names and compass numbers together, one of the two has been imported from a system it does not belong to. Which one to trust depends on which question you are asking, and the two questions are separated in two things called a bagua map.

What the numbers are useful for

Read as labels for directions, the Lo Shu numbers are a compact way to talk about sectors — saying “the 1 sector” is shorter than “north” and unambiguous once you know the mapping. They are used that way throughout the compass literature, and in schools beyond Eight Mansions the same numbers move around the plan year by year, which is a different tradition again and not one this site covers.

Read as a reading, they are thin. A number in a sector is not a verdict on the sector. In Eight Mansions what makes a sector favorable or unfavorable is the relationship between the person’s trigram and the sector’s trigram, and the number is a name for the sector rather than the reason for the judgment.

Two things to keep separate, then. The number identifies the direction. The judgment comes from the pairing, and the pairing needs a birth date. The bagua map with directions tool shows both halves on one plan, and the Kua number calculator does the personal half alone, substitution included.