干

Calendar system · 干支

Heavenly Stems & Earthly Branches

Q: What are Heavenly Stems?

Heavenly Stems, or Tiangan, are ten traditional signs: Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, and Gui. In zodiac-year explanations, they are closely tied to the Five Elements and yin-yang layer.

Q: What are Earthly Branches?

Earthly Branches, or Dizhi, are twelve traditional signs: Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, and Hai. They connect with the 12 zodiac animals.

Behind the 12 Chinese zodiac animals is an older counting system: the 10 Heavenly Stems and the 12 Earthly Branches. Together they form the 60-year cycle used in traditional Chinese calendar labels, zodiac years, element names, and timekeeping.

The idea in one minute

If the 12 zodiac animals are the part most English readers recognize, Heavenly Stems and Earthly Branches are the structure underneath. The stem gives the element layer. The branch gives the animal layer. When a stem and a branch are paired, they create a year label such as Jiǎchén 甲辰, known in plain zodiac language as a Wood Dragon year.

Heavenly Stems Tiāngān · 天干

10 signs: Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, Gui. They connect with yin-yang and the Five Elements.

Earthly Branches Dìzhī · 地支

12 signs: Zi through Hai. They connect with the 12 zodiac animals, months, hours, and directions.

60-year cycle Liùshí Jiǎzǐ · 六十甲子

The 10 stems and 12 branches pair in order. The full set returns to the start after 60 combinations.

Useful shortcut:
Animal comes from the Earthly Branch. Element comes from the Heavenly Stem. The full zodiac year needs both.

Stem-branch year calculator

Enter a Gregorian year to see the stem, branch, animal, element, yin-yang quality, and position in the 60-year cycle. For January or February birthdays, remember to check whether the birthday happened before Chinese New Year.

Year Was the birthday before Chinese New Year?

Boundary note:
This tool gives the cycle label for the year you enter. If the birthday is in January or February, the zodiac year may still belong to the previous lunar year. Check the Chinese New Year boundary before using the result for a birth chart or zodiac reading.

The 10 Heavenly Stems

The Heavenly Stems are a set of ten signs. In modern zodiac explanations, they are most useful because they tell you the element and yin-yang layer of a year.

Order	Stem	Pinyin	Element	Yin / Yang	Plain-English note
1	甲	Jiǎ	Wood 木	Yang	Often read as outward, upright, growing Wood.
2	乙	Yǐ	Wood 木	Yin	Often read as flexible, bending, refined Wood.
3	丙	Bǐng	Fire 火	Yang	Often read as bright, visible, outward Fire.
4	丁	Dīng	Fire 火	Yin	Often read as smaller, focused, lamp-like Fire.
5	戊	Wù	Earth 土	Yang	Often read as solid, mountain-like Earth.
6	己	Jǐ	Earth 土	Yin	Often read as cultivated, field-like Earth.
7	庚	Gēng	Metal 金	Yang	Often read as firm, raw, decisive Metal.
8	辛	Xīn	Metal 金	Yin	Often read as refined, precise, jewel-like Metal.
9	壬	Rén	Water 水	Yang	Often read as large, flowing, river-like Water.
10	癸	Guǐ	Water 水	Yin	Often read as gentle, hidden, rain-like Water.

The 12 Earthly Branches and zodiac animals

The Earthly Branches are the part that connects directly with the 12 animals. When people say “Rat year” or “Dragon year,” they are using the animal name attached to the branch.

Order	Branch	Pinyin	Animal	Chinese animal	Traditional hour
1	子	Zǐ	Rat	鼠 shǔ	23:00–00:59
2	丑	Chǒu	Ox	牛 niú	01:00–02:59
3	寅	Yín	Tiger	虎 hǔ	03:00–04:59
4	卯	Mǎo	Rabbit	兔 tù	05:00–06:59
5	辰	Chén	Dragon	龙 lóng	07:00–08:59
6	巳	Sì	Snake	蛇 shé	09:00–10:59
7	午	Wǔ	Horse	马 mǎ	11:00–12:59
8	未	Wèi	Goat	羊 yáng	13:00–14:59
9	申	Shēn	Monkey	猴 hóu	15:00–16:59
10	酉	Yǒu	Rooster	鸡 jī	17:00–18:59
11	戌	Xū	Dog	狗 gǒu	19:00–20:59
12	亥	Hài	Pig	猪 zhū	21:00–22:59

How the 60-year cycle works

The cycle begins with 甲子 Jiǎzǐ. The next pair is 乙丑 Yǐchǒu, then 丙寅 Bǐngyín. The stem advances one step and the branch advances one step at the same time. Because there are 10 stems and 12 branches, they do not return to the same pairing until 60 steps later.

This is why the zodiac animal repeats every 12 years, but the complete animal + element label repeats every 60 years. A Dragon year comes every 12 years. A Wood Dragon year comes every 60 years.

12-year animal loop

Rat to Pig repeats every 12 years through the Earthly Branches.

10-stem element loop

Wood, Fire, Earth, Metal, and Water repeat through the 10 stems.

60-year full loop

Stem + branch returns to the same pair only after 60 combinations.

First 12 pairs in the cycle

The full cycle has 60 pairs. These first 12 show how the pattern moves: stem forward, branch forward, animal forward.

Cycle #	Pair	Pinyin	Animal	Element label
1	甲子	Jiǎzǐ	Rat	Wood Rat
2	乙丑	Yǐchǒu	Ox	Wood Ox
3	丙寅	Bǐngyín	Tiger	Fire Tiger
4	丁卯	Dīngmǎo	Rabbit	Fire Rabbit
5	戊辰	Wùchén	Dragon	Earth Dragon
6	己巳	Jǐsì	Snake	Earth Snake
7	庚午	Gēngwǔ	Horse	Metal Horse
8	辛未	Xīnwèi	Goat	Metal Goat
9	壬申	Rénshēn	Monkey	Water Monkey
10	癸酉	Guǐyǒu	Rooster	Water Rooster
11	甲戌	Jiǎxū	Dog	Wood Dog
12	乙亥	Yǐhài	Pig	Wood Pig

The cycle does not reset when the animal list reaches Pig. The stems continue too, which is why the next Rat year is not always the same element.

Why this matters for Chinese zodiac pages

A simple zodiac chart may only show animals. That is fine for a quick answer, but it hides the deeper label. In traditional year naming, the animal is only the branch side. The stem side gives the element and yin-yang quality.

This is why The Zodiac Lore usually writes a year as animal + element when the page needs precision: Fire Horse, Wood Dragon, Earth Tiger, Metal Rat, Water Rabbit. These are not random style choices. They come from the stem-branch pairing.

Common mistakes

Thinking the zodiac is only 12 animals. The animals come from the 12 Earthly Branches, but the full year label also includes a Heavenly Stem.
Calling the element “the animal’s element.” The element comes from the stem of that year, not from the animal itself.
Forgetting the 60-year cycle. The animal repeats every 12 years, but the full stem-branch label repeats every 60 years.
Using January 1 for birth-year results. For January and February birthdays, check the Chinese New Year boundary first.

FAQ

What are Heavenly Stems?

Heavenly Stems, or Tiāngān 天干, are ten traditional signs: Jia, Yi, Bing, Ding, Wu, Ji, Geng, Xin, Ren, and Gui. In zodiac-year explanations, they are closely tied to the Five Elements and yin-yang layer.

What are Earthly Branches?

Earthly Branches, or Dìzhī 地支, are twelve traditional signs: Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, and Hai. They connect with the 12 zodiac animals.

Why is the cycle 60 years?

The system pairs 10 Heavenly Stems with 12 Earthly Branches in order. Because 10 and 12 meet again at 60, the full stem-branch cycle contains 60 combinations.

Does the animal come from the stem or the branch?

The animal comes from the Earthly Branch. For example, Chen 辰 is associated with Dragon, and Wu 午 is associated with Horse.

Where does the element come from?

The element comes from the Heavenly Stem. Jia and Yi are Wood, Bing and Ding are Fire, Wu and Ji are Earth, Geng and Xin are Metal, and Ren and Gui are Water.

Is this the same as a full BaZi chart?

No. This page explains the stem-branch system behind zodiac years. A full BaZi chart uses year, month, day, and hour pillars.

Next steps

The Five Elements Understand Wood, Fire, Earth, Metal, and Water. Explore elements → 60-year cycle guide See how the full cycle repeats. Open guide → January / February rule Check the Lunar New Year boundary. Read the rule →

Editorial note

This page explains Heavenly Stems and Earthly Branches for zodiac and calendar learners. It is a cultural and educational guide, not a complete BaZi or fortune-telling system. For birth-year results near January or February, The Zodiac Lore checks the Chinese New Year boundary before assigning an animal and element label.