BAZI FUNDAMENTALS
The ten Heavenly Stems (天干) are the building blocks of a BaZi chart — five elements, each in a Yang and a Yin form. Each stem carries its own natural image and temperament, and the stem of your birth day, your Day Master, is the lens the whole chart is read through.
Wood, Fire, Earth, Metal and Water, each split into an outward Yang expression and an inward Yin one. Tap any stem to jump to it.
Jia
The towering tree
Upright, growth-driven, a natural first mover.
Jia is Yang Wood — the tall, straight tree that reaches for the sky. It carries a strong sense of direction and principle, likes to lead and to build things that last, and can grow rigid when bent against its will.
Day pillars with this stem
Yi
Grass, vine and flower
Flexible, resilient, quietly gets its way.
Yi is Yin Wood — the vine and flowering plant that bends without breaking. Adaptable and tactful, it finds the sunlight by winding around obstacles rather than confronting them, with a soft surface over real tenacity.
Day pillars with this stem
Bing
The sun
Radiant, warm, impossible to ignore.
Bing is Yang Fire — the sun itself: bright, outgoing, and generous with its energy. It lights up a room and shares warmth freely, though the same blaze can turn showy or burn hot when unchecked.
Day pillars with this stem
Ding
Candle and starlight
Gentle, attentive, warmth with focus.
Ding is Yin Fire — the candle flame and evening star: a softer, steadier light. Perceptive and caring, it warms the people close to it and works with quiet concentration, sometimes keeping its inner fire hidden.
Day pillars with this stem
Wu
The mountain
Solid, dependable, hard to move.
Wu is Yang Earth — the mountain and broad plain: grounded, steady, and protective of those it shelters. It offers reliability and calm under pressure, and can be as immovable as it is trustworthy.
Day pillars with this stem
Ji
The fertile field
Nurturing, resourceful, quietly cultivating.
Ji is Yin Earth — garden soil and cultivated field: soft, giving, and endlessly productive. It nurtures growth in others and prefers to accommodate rather than command, hiding real depth beneath a modest surface.
Day pillars with this stem
Geng
Sword and raw ore
Decisive, tough, straight to the point.
Geng is Yang Metal — the blade and unrefined ore: strong, direct, and built for action. It values fairness and getting things done, cuts through hesitation, and can come across as blunt when softness is called for.
Day pillars with this stem
Xin
Jewel and fine metal
Refined, precise, an eye for quality.
Xin is Yin Metal — the polished jewel and delicate ornament: elegant, exact, and sensitive to how things look and feel. It has real taste and high standards, and can be proud or easily stung when its worth goes unseen.
Day pillars with this stem
Ren
River and ocean
Expansive, clever, always in motion.
Ren is Yang Water — the great river and open sea: broad-minded, resourceful, and hard to contain. It thinks big, adapts quickly, and craves freedom, though its restless current can scatter without a channel to follow.
Day pillars with this stem
Gui
Dew, rain and stream
Gentle, intuitive, quietly perceptive.
Gui is Yin Water — dew, soft rain and the small stream: subtle, imaginative, and deeply intuitive. It reads moods without being told, adapts to any container it fills, and keeps much of its inner world private.
Day pillars with this stem
| Stem | Pinyin | Element | Polarity | Natural image | Keywords |
|---|---|---|---|---|---|
| 甲 | Jia | Wood | Yang | The towering tree | Principled · Pioneering · Ambitious · Stubborn |
| 乙 | Yi | Wood | Yin | Grass, vine and flower | Adaptable · Resilient · Tactful · Practical |
| 丙 | Bing | Fire | Yang | The sun | Warm · Outgoing · Generous · Dramatic |
| 丁 | Ding | Fire | Yin | Candle and starlight | Warm · Perceptive · Focused · Reserved |
| 戊 | Wu | Earth | Yang | The mountain | Steady · Reliable · Protective · Stubborn |
| 己 | Ji | Earth | Yin | The fertile field | Nurturing · Accommodating · Resourceful · Understated |
| 庚 | Geng | Metal | Yang | Sword and raw ore | Decisive · Tough · Just · Blunt |
| 辛 | Xin | Metal | Yin | Jewel and fine metal | Refined · Precise · Aesthetic · Proud |
| 壬 | Ren | Water | Yang | River and ocean | Broad-minded · Resourceful · Free-spirited · Restless |
| 癸 | Gui | Water | Yin | Dew, rain and stream | Intuitive · Imaginative · Adaptable · Private |
A stem is never read in isolation — its meaning comes from where it sits and what it touches. Four ideas do most of the work.
The stem of your birth day represents you. Whether it is strong or weak, and which elements support or drain it, sets the whole strategy of the reading.
Every other stem is labelled by its relationship to the Day Master — resource, output, wealth, authority, or peer. These 'Ten Gods' turn raw elements into life themes like career, money, and relationships.
Certain stems pair off and 'combine', softening or transforming their nature. These bonds explain attractions, compromises, and sudden shifts in a chart.
Your luck periods and each new year arrive as stems too. How they interact with your Day Master is what makes one year feel supportive and another demanding.
When these paired stems meet, they bond and lean toward a new element — the classic 天干五合. It is one of the first patterns a reader looks for.
The five Yang stems follow qi, not circumstance; the five Yin stems follow circumstance, without sentiment.Di Tian Sui (滴天髓)
This famous line captures the core difference in temperament: Yang stems (Jia, Bing, Wu, Geng, Ren) tend to act on principle and momentum, while Yin stems (Yi, Ding, Ji, Xin, Gui) read the situation and adapt. Neither is better — they simply move through the world differently.
They are ten symbols — 甲乙丙丁戊己庚辛壬癸 (Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, Gui) — that pair the five elements with Yin and Yang. Together with the twelve Earthly Branches they form the sixty-year cycle used throughout Chinese astrology.
Zodiac signs are the twelve Earthly Branches (Rat, Ox, Tiger…). The Heavenly Stems are the other half of the pair — the elemental layer. Your day's stem, the Day Master, says more about your core temperament than your zodiac animal alone.
The one that matters most is your Day Master — the stem of your birth day. It cannot be read from the calendar date directly. Enter your birth date, time and city into the free calculator below and it will show your Day Master and full Four Pillars.
No stem is inherently lucky or unlucky. Each has natural strengths and blind spots, and its quality depends entirely on the rest of the chart — the season of birth and the other stems and branches around it.
Was this article helpful?
Calculate your full BaZi chart free — with longitude correction — and see which of the ten stems is your Day Master.
Calculate my chart free
