The Ten Heavenly Stems, Explained Simply
5 min read · Updated 2026-09
A ten-letter alphabet of energy
The Heavenly Stems (天干) are a ten-character cycle: Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, Gui. Each stem is one of the five elements in a Yin or Yang polarity — Yang Wood, Yin Wood, Yang Fire, and so on. Stems combine with the twelve Earthly Branches to build every BaZi chart.
In a chart, the stems you can see are the four visible 'actors': the year stem (ancestry and early environment), month stem (career climate), day stem (you — the Day Master), and hour stem (later life and protégés).
Combinations change the story
Certain stem pairs combine (天干五合): Jia with Ji, Yi with Geng, Bing with Xin, Ding with Ren, Wu with Gui. When two combining stems sit close in a chart, their energies bond and can transform — a classical reading treats this as a major structural event, and compatibility analysts treat it as a hidden second personality.
Stems also relate by generation and control, exactly like the five elements beneath them: a stem that generates your Day Master supports you; one that controls it pressures you. Counting these relationships is how a chart turns from a list of characters into an argument.
Where to start
Find your Day Master first — the day stem. Its element and polarity are the lens for everything else in the chart. The free reading names it for you and reads the stems around it.
See it in your own chart
Free, no signup — astronomically precise pillars, corrected for your birth city's true solar time.
Find your Day Master →