Calculating and Combining Two Axes
The matching rate comes from two branches. Saju compatibility looks at the entire saju original chart of both individuals, while zodiac compatibility only considers one earthly branch from the year of birth. The final value is obtained by weighted averaging the two.
| Axis | What is Considered | Weight |
|---|---|---|
| Saju Compatibility | Day stem, day branch, and the five elements — four items | 70% |
| Zodiac Compatibility | The relationship between the year branches | 30% |
The saju side is much heavier because the amount of information used is different. Saju considers all four pillars, while the zodiac only looks at one character. However, the zodiac is not excluded for two reasons — it is the most intuitively understandable item, and it is the only axis whose value does not fluctuate even without knowing the birth time.
The Four Items of Saju Compatibility
The saju side is further divided into four. Each item is chosen to ensure that what they consider does not overlap.
Year Pillar
Heavenly Stem
Earthly Branch
Root · Zodiac
Month Pillar
Heavenly Stem
Earthly Branch
Season · Power
Day Pillar
Heavenly StemDay Stem = Me
Earthly BranchDay Branch = Spouse Palace
Me · Spouse Palace
Hour Pillar
Heavenly Stem
Earthly Branch
Later Years · Usage
| Item | What is Considered | Weight |
|---|---|---|
| Day Stem Relationship | What the two people's day stems (日干) are to each other — viewed through the Ten Gods | 32% |
| Five Elements Complementation | Does the partner have the energy I need — viewed through the supporting element a chart currently needs | 25% |
| Spouse Star | Does the partner's day stem correspond to my spouse position? | 23% |
| Day Branch Relationship | Are the two people's day branches (日支) a combination or a clash? | 20% |
The day branch is read because the tradition treats it as the spouse palace. Of the four pillars it is the one that points at the partner, which makes it the first place compatibility looks.
If the gender is not disclosed, the spouse element is omitted
The spouse element requires knowledge of gender for calculation. The tradition reads the position that points at a spouse differently depending on gender. If not disclosed, this item will be excluded and the weights of the remaining three items will be renormalized.
Calculations can be done without knowing the birth time
The birth time is used to determine the hour pillar. If unknown, calculations will be done without the hour pillar, and this fact will be indicated on the results screen. Since there is no direct input for the hour pillar among the four compatibility items, the values will not fluctuate significantly, but it does affect the balance of the five elements.
If you know the time, please also select the place of birth. If the standard time differs from the actual solar position, using it as is may misalign the hour pillar (true solar time correction).
The same input will always yield the same value
All scores are determined by rules. No artificial intelligence is used, nor are random numbers employed. Therefore, entering the same two birth dates multiple times will not yield different results. As a service that does not store data, previous results cannot be retrieved, but determinism compensates for that.
What this result is not
This is a reference material calculated from rules built on the perspective of the tradition. It is not a scientific prediction, nor is it a definitive statement about the relationship between the two individuals. The score range is set to a minimum of around 45 points for this reason — no combination will yield a value close to 0 points.