BaZi Compatibility Calculator

What BaZi compatibility actually measures

BaZi compatibility is not a single yes-or-no verdict. It separates two charts into three layers and reads each one. Look at all three and the conclusion holds up; look at only one, especially the zodiac animal, and the reading goes wrong easily.

Layer one: the Spouse Palace (day branch)

The day stem is the Day Master, the person themselves. The day branch is the Spouse Palace, the way someone behaves inside an intimate relationship. Whether the two Spouse Palaces form a Six Harmony, a Three Harmony, a Six Clash, a Six Harm or a Punishment decides whether daily rhythm syncs naturally or has to be negotiated. This layer carries the most weight, worth roughly minus twenty to plus eighteen points here.

Layer two: the Day Master elements

The two Day Master elements either generate, match or control each other. Generating pairs, such as Wood feeding Fire, are traditionally read as mutual support, though the real risk is one-sided giving. Controlling pairs, such as Wood controlling Earth, are often misread as a bad sign. In practice they mean one partner naturally takes the lead, which becomes a strength once roles are made explicit.

Layer three: the hour and year branches

The hour pillar speaks to later life and long-range planning. Matching hour branches mean similar timing on decisions about children, ageing parents and money; clashing hour branches mean those same topics need to be negotiated early rather than assumed. The year branch is the zodiac animal and the family layer around the couple. It uses only one character, so this tool treats it as a hint and leaves it out of the score.

Why zodiac-only matching is not enough

Zodiac matching uses the year branch alone: one character out of eight. Two people born in the same year can have completely different Spouse Palaces. If one has a Zi day branch and the other a Wu day branch, that is a Six Clash; swap in a Chou day branch and the same Zi becomes a Six Harmony. Identical zodiac animals, opposite outcomes. Use the zodiac animal to start a conversation, not to end one.

How the score is calculated

The formula is published so you can check it. Start at 68 and adjust on three items:

• Day branches: Six Harmony +18, Three Harmony +6, Six Clash -20, anything else 0
• Day Master elements: generating +12, identical +8, controlling -10, unrelated 0
• Hour branches: identical +6, clashing -4, anything else 0

The total is clamped between 35 and 99 so no meaningless extremes appear. Bands map to five conclusions: 90 and above is an excellent match, 80 to 89 a strong match, 70 to 79 workable with effort, 60 to 69 more friction than average, and below 60 proceed with care.

How the charts are calculated

Schools differ on details, so here is exactly what this tool does, in case you want to compare it against another calculator.

• The year pillar switches at Li Chun (Start of Spring), not at Chinese New Year. This is standard practice in BaZi.
• The month pillar switches at the twelve "jie" nodes, and the month stem is derived with the Five Tigers rule.
• The day pillar is derived from the Julian Day Number, which maps one-to-one to the Gregorian date and is timezone independent.
• The hour pillar uses the twelve two-hour Chinese hours, with the hour stem derived by the Five Rats rule.
• Solar term data covers 1900 to 2099 and is accurate to the hour of the node, not just the date.
• The Zi hour is treated as belonging to the given date (early-Zi convention). If you follow the late-Zi convention, day pillars for births after 23:00 will differ by one day.

How to read your result

First, do not treat the number as a verdict. Compatibility measures how much friction a pairing tends to produce, not how much the relationship is worth. A low score usually concentrates in one item, such as a day-branch clash that signals very different communication styles, and that is something a couple can work around by agreeing on how they argue. A very high score is not risk-free either: a Six Harmony Spouse Palace can make a couple so comfortable that they postpone long-range planning.

Second, look at which item pulled the score down rather than at the total. The flagged item in the reading is where the real work is. A pairing that is unremarkable on every item usually holds up better than one that is extreme on two.

Third, add the birth hour if you left it out. Rerun once you know it and the hour item will fill in.

Frequently asked questions

Does a low score mean we should not marry?

No. The score measures how much friction the pairing tends to produce, not the value of the relationship. A low score usually means one specific layer needs extra handling, such as a day-branch clash, which signals very different communication styles. Knowing where the friction sits is more useful than not knowing at all.

Can I run this without knowing the exact birth hour?

Yes. The birth hour only affects the hour pillar, and in the scoring the hour branch is a single item worth plus six for an identical branch or minus four for a clash. Leaving it out changes nothing else. The year, month and day pillars already give you the Day Master and the Spouse Palace.

Is BaZi compatibility more accurate than zodiac sign matching?

Zodiac matching uses only the year branch, one character out of eight. BaZi compatibility reads the full chart: the day branch is the Spouse Palace, the day stem is the person, and the hour branch speaks to long-term planning. One character is a first impression, not a verdict.

Will I get the same result every time I run it?

Yes. This calculator uses no random numbers. The pillars and the score are determined entirely by the birth date and hour you enter, so the same input gives the same output on any device at any time, and you can check it against the published formula.