Compatibility read from two birth dates

Enter two birth dates and four things come back as tables and diagrams: the phase relationships that qualify, how far the two ranges of action overlap, stem combination (Kango), and the Tenchusatsu tie between you. The rest of this page walks through each of the four.

These four are not all there is to compatibility. Guardian Element, the producing and restricting cycles of the Five Elements, the timing each person is passing through — other methods exist. What this page does not cover is gathered near the end.

All it uses is two birth dates and gender. For the same two people the result never changes, however many times you run it. Nothing is drawn at random: once the birth dates are fixed, the structure is fixed, and the tables and diagrams simply show it.

Each person's Year, Month, and Day pillars are placed on a circle as three of the sixty stem-branch numbers, and the three points are joined. Usually this makes a triangle, and that shape is the person's range of action.

Lay two of them on the same circle and the two shapes fall into three broad arrangements.

A partial overlap means shared ground with a stretch of the other person's world still unknown to you. There is a part where you understand each other and a part that stays interesting precisely because you do not. This is read as a good match, and one where the tie tends to run deep.

A near-total overlap means two people who move in almost the same way. It is comfortable. But being that close is itself the difficulty: you both get stuck at the same point, so neither of you can open a way out for the other. The closeness and the deadlock are the same thing.

No overlap at all means two ranges of action sitting in different places. Values do not line up, and it takes time to follow how the other person thinks. This is the arrangement people most often come here worried about — but not overlapping does not by itself decide the quality of a relationship.

There is also a case where a complete non-overlap is not read at face value. If the two are more than ten years apart in age, or come from different countries — if the backgrounds they live in already differ that much — then not overlapping is not treated as a problem. Of course it differs.

Phase analysis names the relationships that stem-branch pairs form. The compatibility table crosses each person's Year, Month, and Day pillars against the other's, and every cell holds whichever relationship qualifies. Listed out, the relationships that can appear are these.

Broadly they split into those that gather (combining) and those that loosen or collide (scattering). Scattering does not mean bad. A clash is the shape in which two people face each other head-on and something that had stalled finally moves; a penalty is the shape in which they wear on each other and are strengthened by it. Both turn up perfectly normally in relationships that have lasted for years.

The table also shows which pillar met which. Day pillar to day pillar is where the two natures touch each other directly; year pillar to year pillar is where you mesh on the side of family and society. The same relationship name reaches a different part of life depending on where it formed.

Phase relationships and the Cosmic Board both work on earthly branches. Kango is something else: a relationship between heavenly stems. Five pairs combine — Yang Wood with Yin Earth, Yin Wood with Yang Metal, Yang Fire with Yin Metal, Yin Fire with Yang Water, Yang Earth with Yin Water — transforming into Earth, Metal, Water, Wood, and Fire respectively.

When two people's day stems combine, they are said to be able to become one in feeling: even when other conditions are poor, affection carries them into working together. The same reading also says the tie is hard to dissolve, and can turn into the kind of bond people stay in without quite choosing to. The pull and the difficulty of leaving are two faces of one thing.

There is a second layer. When the heavenly stems combine and the earthly branches are in harmony as well, that is Kango-shigou. This one is not limited to the day pillars — it can form between any of the year, month, and day pillars. Two charts showing Kango-shigou are read as being on unusually good terms.

Below the table you will see whether the two day stems combine, and whether Kango-shigou has formed.

Tenchusatsu is the pair of earthly branches left unassigned to your day stem-branch. Everyone has two, and they mark the area where ordinary support thins out. Between two people, those two branches can connect in two ways.

A shared Tenchusatsu means both people have the same two branches. Your timing cycles rise and fall together, so conversation is quick and the other person is easy to be around. The swings are larger too: the good stretches are good for both of you, and the low stretches pull you both down at once. Kept up over years, it becomes hard to separate — the bond people describe as one they cannot quite leave.

A mutual Tenchusatsu means each person's day-pillar branch falls inside the other's two Tenchusatsu branches. It does not form in one direction only; it requires both directions at once. The two of you move on opposite waves, so when the other is rising you are in a quiet stretch. This is said to mesh better as a working partnership than as a household.

Most pairs have neither. If the table tells you no special tenchusatsu relationship (shared or mutual) has formed, that is the ordinary result — it does not mean the connection between you is thin.

Separately from how much they overlap, the triangles themselves differ in size. A wide range means a person who draws strength from moving between several places; a narrow one means a person who draws strength from digging into a single place. Neither is better.

When two people of different sizes are together, the friction takes a predictable form. The wider one wonders why the other will not move; the narrower one wonders why the other will not settle. The cause is not character. The range in which each of them produces force is simply different.

Once that is clear, there is a move available other than trying to change the other person: divide the roles. One goes outward, one holds the centre. A difference in range is quicker to use than to close.

The same table is read starting from a different place depending on what the relationship is.

Between partners, start around the day pillars. The day pillar stands for the person themselves, so this is where the two of you meet unguarded. Harmony on the day pillars is hard to walk away from; a clash there pulls strongly and unsettles just as strongly.

For a marriage or a household meant to last, the month and year pillars matter more. Whether your ways of living and of meeting society mesh is what decides how much daily friction there is. A relationship that is strong as romance is not necessarily easy as a life.

For a working partnership, look first at the overlap and the size of the ranges. Whether you get along matters less to the result than whether the areas you can move in fit together. Two people who do not overlap at all are sometimes the strongest combination once the work is divided.

These are not the only methods used for compatibility. Here are the ones you will most often meet. None of them appears in this table.

The Guardian Element is the element a given person is short of. One version is derived from the day stem and month branch to balance the season; another comes from the elemental balance of the whole chart. It is originally a method for reading one person, but it is sometimes applied to compatibility by asking whether the other person carries the element you lack.

The producing and restricting cycles of the Five Elements are used as well. Producing runs Wood into Fire, Fire into Earth, and onward; restricting is the holding relation in which Wood restricts Earth and Earth restricts Water. Being restricted is not necessarily bad — the reading is that the restricted side is provoked into growth. There is also a method that overlays two elemental balances to see whether each supplies what the other lacks.

There is compatibility of timing, too. Reading which phase relationships form against the major and annual cycles shows when two people work well together and when they are better off keeping some distance.

All of these read the whole chart. A table built from two birth dates is not enough for them.

None of the four outputs above produces a score. There is no good-compatibility or bad-compatibility line in the chart itself. What there is is the shape of the relationship: alike, interlocking, or far apart.

Without a score it may feel unfinished. But knowing a score would not change how you speak to that person tomorrow. When a relationship is not working, what you need is the answer to why you keep stumbling in the same spot. The tables and diagrams point at that spot.

The tables and diagrams stay free, for as many pairs as you like, with no account. It is the next step — having the AI read what this particular overlap means for these two people — that needs a free account.