Compatibility is the most requested Saju reading and the most often oversimplified. There is no single score, and any service that gives you one out of a hundred has invented it.
What Saju actually offers is a set of named relationships between two charts.
Stem combinations (천간합). Five pairs of heavenly stems combine: 甲–己 · 乙–庚 · 丙–辛 · 丁–壬 · 戊–癸
If your Day Master and theirs form one of these, the two characters bond in the system. It is a structural statement, not a promise. Traditionally each combination also transforms toward a resulting element under the right conditions.
Branch relationships (지지). The earthly branches carry their own set: six harmonies (육합), three-way alliances (삼합), clashes (충), and a few more difficult categories. Branch clashes are where a lot of felt friction shows up, particularly between the day branches — the day branch is traditionally read as the spouse position (배우자궁).
Element exchange. Beyond named pairs, the practical question is whether their chart supplies what yours lacks. A chart short on Fire meeting one heavy in Fire is a different dynamic from two charts short on the same thing.
Three notes worth being honest about:
- Compatibility needs two charts. Your own chart tells you which stem you combine with. Whether it works needs their birth details too. Any reading that claims a full compatibility verdict from one person's data is guessing.
- Tension is not failure. Clash configurations often describe the relationships people find most compelling. The reading describes the shape of the friction, not the outcome.
- This describes patterns, not people. Two people are not obliged to behave like their charts.
For entertainment and self-reflection only. Not advice.