The Sexagenary Cycle

Why Sixty

Two cycles run alongside each other. The ten heavenly stems carry the five elements twice over, once in a yang form and once in a yin; the twelve earthly branches are the ones with animals attached. Both advance a single step each year. The pair therefore returns to its starting point not after 120 years — ten times twelve — but after sixty, the least common multiple of the two. That the product and the multiple differ is the whole structure of the thing, and it has one large consequence.

Ten and twelve share a factor of two, so a stem never meets a branch of the opposite parity. Counting the branches from one, as every page below does, the odd-numbered ones take yang stems only and the even-numbered ones take yin. The Rat is branch 1, and is yang in all five of its variants; the Ox is branch 2, and yin in all five of its. Each animal therefore has exactly five variants rather than ten, and its polarity is not a property of the year but of the animal itself — permanently.

The Ten Heavenly Stems

Five elements, each appearing twice — yang first, then yin. The element and polarity of a stem are not assigned separately from its position: the element is the position halved and the polarity is the position's parity, which is why the table below has no irregularities in it.

Each stem governs six of the sixty years — sixty divided by ten — and those six are always six different animals, never a repeat.

The Twelve Earthly Branches

These carry the animals, and each carries a fixed element of its own that no stem changes. The branch character is what names a year — not the animal character, which is a different glyph entirely and appears in the second row of each cell below for comparison.

All Sixty, in Cycle Order

Position one is 甲子, the yang Wood Rat — the combination that begins the round, and the reason 1984 and 1924 are treated as cycle starts. Each row shows the pair, the position, the years it falls on between 1900 and 2100, and how the stem's element sits on the branch's own.

The years column, read across all sixty rows, covers every year from 1900 to 2100 once and once only — 201 years, partitioned with no gaps and no overlaps. A Chinese year runs from one lunar new year to the next, not from 1 January. A January birthday belongs to the row above.

The Five Ways a Stem Sits on a Branch

Every animal carries a fixed element; every year lays another over it. Under the generating and controlling cycles of the five phases there are exactly five ways those two can stand, and the sixty divide evenly between them — twelve each, one per animal. So this cannot rank animals against one another. What it does is distinguish an animal's own five variants, and it does that completely: each animal's five fall in five different relations, so no two variants of the same animal share a description.

Each combination page states its own relation and what tradition reads into it, labelled as a traditional reading. None of them says a year is lucky or unlucky, and the twelve-way even split is the reason: a property shared by twelve of sixty in a fixed pattern is a classification, not a forecast.

By Animal and Element

The same sixty arranged as a grid. Every cell is filled — each animal really does take all five elements — and the polarity in the row label is the only one that animal ever has.

The diagonal worth noticing: 12 of the sixty put an element over itself, because the stem happens to match the animal's own fixed element — one per animal, and the ones almanacs single out. They are Earth Dragon, Earth Ox, Earth Dog, Fire Horse, Water Rat, Wood Tiger, Wood Rabbit, Fire Snake, Earth Goat, Metal Monkey, Metal Rooster and Water Pig.

Sexagenary Cycle FAQs

Where to Go Next

For an animal's character, its compatibility rules, the double hour it governs and the people born under it, the twelve branch pages cover all of that once each. To go from a birth year straight to its animal, element and polarity, the Chinese zodiac calculator handles 1900 to 2100. And for a Vedic reading, which works from a birth chart rather than a year name, start with a free kundli.