Chinese Zodiac Compatibility: The Full Guide
Count the gap between two birth years on the twelve-animal wheel and you can predict, correctly, which of five outcomes our compatibility section gives that pair — before you've looked it up. That's really all this guide teaches: the formula, not the folklore behind it.
The formula
Four years apart, either direction: a San He trine, one of the strongest matches available. Six years apart, sitting directly opposite: a clash, the hardest match on paper. One specific animal, off the regular spacing pattern: a Liu He "secret friend," stronger even than a trine. Everything else — the majority of all 66 possible pairings — is neutral. The mechanics and origin of San He and Liu He get their own full treatment in our San He and Liu He explainer; this page is about what each category means once you're standing in front of an actual pairing.
Try it on a real pair
Take a Rat and a Dog. Count from Rat (position 1) to Dog (position 11): that's ten steps forward, or two back the other way — take the shorter path, so two apart. Two doesn't match any of the named gaps (four, six, or the fixed Liu He list), so before checking anything else, this pair is already looking neutral. Now take a Rat and a Dragon: four apart, a trine, no further checking needed. A Rat and a Horse: six apart, opposite ends of the wheel, a clash. This is the entire method — count the gap, or count backward if that's shorter, and match it against four, six, or the six memorized Liu He pairs. No birth month, no hour, no deeper reading required for this layer of the system.
One wrinkle worth flagging: gap-counting alone doesn't catch harm pairs, since those aren't defined by a fixed spacing the way trines and clashes are — Rat and Goat, for instance, sit five apart by the shorter count, which the spacing rule alone would call neutral. Harm pairs are, like the Liu He list, six specific pairs to check separately rather than compute.
One more: Rat and Ox. Count the gap and you get one — nowhere near four or six, so the spacing rule says neutral. But Rat–Ox is on the Liu He list, the strongest possible reading, not a middling one. This is the actual reason the compatibility section can't be reduced to a single formula: gap-counting alone gets you trines, clashes, and (by elimination) most of the neutral cases, but the two named lists — Liu He and harm — have to be checked on top, because they're defined by tradition as specific pairs rather than by distance. Miss that step and a Rat-Ox couple looks like a coin flip instead of the best match either animal has.
Six years apart: the clash pairs (六冲)
Sit directly opposite each other on the wheel and you get a clash: Rat–Horse, Ox–Goat, Tiger–Monkey, Rabbit–Rooster, Dragon–Dog, Snake–Pig. Hardest matches on paper, not doomed ones. The usual arc: strong initial attraction, opposites genuinely drawing each other in, followed by a longer negotiation over control and pace once things settle.
The harm pairs (六害)
Milder than a clash: Rat–Goat, Ox–Horse, Tiger–Snake, Rabbit–Dragon, Monkey–Pig, Rooster–Dog. Not head-on conflict — small misunderstandings that build up quietly if nobody talks them through.
Everything else
Subtract the triangles, secret friends, clashes and harm pairs and most of the 66 combinations are left over, unclassified. Tradition calls these neutral — the outcome rests on the two people, not their birth years. Our full compatibility section lists which of the five buckets any specific pair falls into.
Not just romance
The same categories cover business partnerships, friendships, even parent-child relationships. A matchmaker checking a couple's animals before an engagement — see our marriage compatibility guide — is running the identical framework a family elder might apply before going into business with someone, or the same one a parent might use, half-seriously, to explain why one child was always the easy one and the other took more patience.
What a "clash" doesn't mean
People read a clash as "don't get together." That's not the traditional framing. Same six-year gap that makes them opposite also makes the attraction real; the tradition itself describes it that way. Clash predicts friction, not failure — plenty of strong relationships are "difficult" matches on paper that both people simply worked at. Treat any result here the way you'd treat a compatibility quiz in a magazine: a reason to notice a pattern, never a reason to write someone off before you've actually met them.