Hidden stems (藏干)

The table

The main stem is listed first; it is the same element as the branch. The others are secondary (中气) and residual (余气) stems.

This is the arrangement used by the overwhelming majority of modern charts, including ours. It matches the mnemonic verse in Yuan Hai Zi Ping:

子宫癸水在其中，丑癸辛金己土同；寅宫甲木兼丙戊，卯宫乙木独相逢。辰藏乙戊三分癸，巳中庚金丙戊丛；午宫丁火并己土，未宫乙己丁共宗。申位庚金壬水戊，酉宫辛金独丰隆；戌宫辛金及丁戊，亥藏壬甲是真踪。

“In the palace of Zi is Gui water; Chou holds Gui, Xin metal and Ji earth together. The Yin palace has Jia wood with Bing and Wu; in the Mao palace Yi wood is met alone. Chen stores Yi and Wu with a third part of Gui; in Si are Geng metal, Bing and Wu. The Wu palace has Ding fire with Ji earth; the Wei palace shares Yi, Ji and Ding. The Shen position has Geng metal, Ren water and Wu; in the You palace Xin metal flourishes alone. The Xu palace has Xin metal with Ding and Wu; Hai stores Ren and Jia — this is the true trace.”

— Yuan Hai Zi Ping 《淵海子平》, 又地支藏遁歌. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

Why branches contain stems

The Di Tian Sui commentary describes the chart as three layers — the stems as the heavenly origin, the branches as the earthly origin, and “what is within the branches” as the human origin. San Ming Tong Hui develops the same idea, calling the hidden stems the “human origin” and the “spirit that manages affairs” (司事之神):

故支吕所藏者主命，谓之人元，名为司事之神，以命术言之为月令。

“So what is stored within the branches governs fate; it is called the human origin and named the spirit that manages affairs — in the art of fate, it is the month command.”

— San Ming Tong Hui 《三命通會》, 卷二 · 论人元司事. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

The logic of the table follows the seasons and the twelve growth stages. Each branch contains its own element as the main stem. The four “growth” branches 寅 申 巳 亥 also contain the element that is born there (fire is born in 寅, water in 申, metal in 巳, wood in 亥). The four “storage” branches 辰 戌 丑 未 are earth, and also store the element of the season just ending plus the element whose “tomb” they are. The four “peak” branches 子 午 卯 酉 are pure, except 午, which also holds 己 earth.

Which hidden stem is “in charge”: day counts in the month

For the month branch, classical texts go further: they say each hidden stem is in charge for a certain number of days after the start of the month. San Ming Tong Hui gives a full list; its first three months read:

如正月建寅，寅中有艮土用事五日，丙火长生五日，甲木二十日；二月建卯，卯中有甲木用事七日，乙木二十三日；三月建辰，辰中有乙木用事七日，壬水墓库五日，戊土一十八日；

“For example, the first month is established in Yin: in Yin, Gen earth is in charge for five days, Bing fire, which is born there, for five days, and Jia wood for twenty days. The second month is established in Mao: in Mao, Jia wood is in charge for seven days and Yi wood for twenty-three days. The third month is established in Chen: in Chen, Yi wood is in charge for seven days, Ren water in its tomb for five days, and Wu earth for eighteen days.”

— San Ming Tong Hui 《三命通會》, 卷二 · 论人元司事. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

Notice two things. First, the list is about time within the month, and it contains stems that are not in the standard table (for example 甲 in 卯 and 壬 in 辰, the “left-over” energy of the previous month or the tomb of an element). Second, other classical sources give different day counts — Yuan Hai Zi Ping has its own verse with different numbers, and the Di Tian Sui commentary uses yet another split for 寅 (7, 7 and 16 days). These schemes are used by some practitioners to decide which hidden stem defines the chart’s structure. The standard table above is used for everything else.

如寅月生人，立春後七日前，皆值戊土用事，八日後十四日前，丙火用事，十五日後，甲木用事，知此則可以取格，可以取用矣

“For example, for a person born in the Yin month: within seven days after Li Chun, Wu earth is in charge; from the eighth to the fourteenth day, Bing fire is in charge; after the fifteenth day, Jia wood is in charge. Knowing this, one can determine the structure and the useful god.”

— Di Tian Sui (Drops from Heaven’s Marrow) 《滴天髓》, 月令論. Original text: Wikisource · also on ctext.org (different edition). Translation: bazimethod.

How hidden stems are used

• Roots. A visible stem is “rooted” when the same element appears among the hidden stems, especially as a main stem. A rooted stem is strong; an unrooted stem “floats”. This is a key part of judging the Day Master’s strength.
• Ten gods. Each hidden stem gets a ten-god label relative to the Day Master. A ten god that is hidden but not visible is said to be latent; one that is both hidden in the month branch and visible among the stems (透干) is prominent and is the usual basis for naming the chart’s structure.
• Clashes and storage. When a storage branch is clashed, classical texts say its hidden stems are released — the “storehouses benefit from being opened” principle on the branches page.

Weighting the hidden stems

Should a residual stem count as much as a main stem? No classical source gives a single numerical answer. Many modern practitioners count the main stem as the most important and the residual stem as the least, and some software assigns percentages. Our calculator counts the hidden stems separately from the eight visible characters and does not weight them, so you can see the raw structure without an invented formula.

Common questions

Why do some sites show different hidden stems?

Almost all modern sources agree on the table above. Differences usually come from the day-count schemes (人元司事), which list more stems for the month branch and change with the number of days since the solar term. A few older traditions also add 戊 or 己 to more branches. If a site shows, for example, 甲 inside 卯, it is probably using a day-count scheme for the month branch.

Do hidden stems count as much as visible stems?

Traditionally, no. A visible stem acts openly; a hidden stem acts through its branch and is strongest when it is the branch’s main stem or when it is also visible (“revealed”). Practitioners often describe a hidden ten god as a latent theme in a life, and a revealed one as an obvious theme. This is interpretation, not arithmetic, and different authors weigh it differently.

Which hidden stem matters most?

The main stem of the month branch, because it carries the season. Next come the hidden stems of the day branch, which sit directly under the Day Master and give it a root (or deny it one).

See them in your chart

The calculator lists the hidden stems under each branch, with their element colour and ten-god label. Look first at the month branch: its main hidden stem tells you the dominant energy of your birth season.

Keep learning

Classical quotations are copied from the public-domain texts on Wikisource; links let you check every line. English translations are our own. Traditional Bazi statements are reported as tradition, not as fact.