A number-based reading created by Chen Tuan in the Song dynasty, joining the He Tu and Luo Shu diagrams with the I Ching. Your BaZi becomes Heaven and Earth numbers, those numbers become an innate hexagram, and the hexagram becomes a map of how your life moves.
The origin
He Luo Li Shu is the most mathematical branch in the whole Chinese I Ching tradition. It converts the heavenly stems and earthly branches of your BaZi into numbers, casts a hexagram from those numbers, and reads your life through the hexagram. Where other systems work through the five elements or through star charts, this one drops straight to the layer underneath, which is number. The old line says one gives birth to two, two to three, and three to everything. He Luo Li Shu goes looking for that first number.
Chen Tuan and Mount Hua
The system is credited to Chen Tuan, who lived roughly 871 to 989, through the late Five Dynasties and into the early Song. He took the Daoist name Xiyi and spent his life in retreat on Mount Hua. His place in Chinese intellectual history is unusual. He worked as neither a plain Daoist nor a plain Confucian, and he reorganised the He Tu and Luo Shu diagrams, the Taiji diagram and the earlier arrangement of the eight trigrams, then passed them on to Song thinkers including Shao Yong, 1012 to 1077, and Zhou Dunyi, 1017 to 1073. A large part of the cosmology that Song and Ming Neo-Confucianism was built on traces back through him.
The name He Luo Li Shu itself is less well documented. Scholars still argue about when the surviving book was written and who wrote it. Some read it as Chen Tuan's own work, others as a later text published under his name. Whoever wrote it, the mathematical logic inside holds together on its own terms.
How the Heaven and Earth numbers are derived
The calculation runs like this. Each heavenly stem takes its Luo Shu number through the Na Jia correspondence, so Ren and Jia take 6 from Qian, Yi and Gui take 2 from Kun, Geng takes 3 from Zhen, Xin takes 4 from Xun, Bing takes 8 from Gen, Ding takes 7 from Dui, Wu takes 1 from Kan and Ji takes 9 from Li. Each earthly branch takes its He Tu generation numbers and contributes one odd and one even value, so Hai and Zi give 1 and 6, Yin and Mao give 3 and 8, Si and Wu give 2 and 7, Shen and You give 4 and 9, and Chen, Xu, Chou and Wei give 5 and 10. Every odd value added together is the Heaven number, standing for what you were born with. Every even value added together is the Earth number, standing for the environment around you. The Heaven number is reduced by 25 and the Earth number by 30, and the reduced value selects a trigram through the Luo Shu, where 1 is Kan, 2 is Kun, 3 is Zhen, 4 is Xun, 6 is Qian, 7 is Dui, 8 is Gen and 9 is Li. For a yang-year man or a yin-year woman the Heaven trigram sits on top and the Earth trigram below, and the two form a six line hexagram, which is your innate life hexagram. The birth hour then fixes the Yuan Tang line, that line changes, the upper and lower trigrams swap, and the result is your acquired life hexagram.
Yuan Tang is the idea that belongs to this system alone. Your birth hour picks out one line among the six and makes it the core coordinate of the reading. The major luck cycles are counted forward from that line, with each line governing a set number of years.
Underneath, He Luo Li Shu is a mapping. It takes a set of time parameters, your BaZi, converts them to numbers, and converts those numbers into a symbolic system, the hexagram. The mapping is deterministic. The same BaZi always yields the same hexagram, with no randomness at any step.
In the language of information theory the system performs a reduction in dimension. Eight stems and branches, drawn from a space of sixty combinations, are compressed into one six line hexagram, of which there are sixty four. The compression cannot be reversed, which means different birth charts can land on the same hexagram. That is a deliberate trade, resolution given up in exchange for something a person can actually read.
No modern statistical study has tested whether He Luo Li Shu predicts anything. Its structure, though, is built from modular arithmetic, mapping functions and symbolic encoding, and all three can be described precisely in the language of cryptography and computer science. That makes it the easiest of all these systems to put into code.
He Luo Li Shu compresses a life into one hexagram, and its six lines are six cross sections of that life. The scents below do not read the hexagram. They meet you where you are standing in it.
Qian, heaven. You carry everything. The resinous smoke of frankincense lets the grip of I have to hold this up loosen by a finger's width, which is permission for someone to help rather than permission to let go.
Kan, water. You are used to walking through the dark stretch alone. The woody air of cedarwood works like the light at the far end of a tunnel, enough for your feet to know where the next step goes.
Gen, mountain. Standing still is rarely about not wanting to move. It is about not knowing whether moving makes things worse. The clean cut of rosemary carries the sound of someone saying, when the thinking loops, take one step first.
Kun, earth. Carrying comes naturally to you, and declining is the practice. The deep sweetness of rose is an invitation for the ground to remember that it also grows flowers.
Numbers make the hexagram, and the hexagram mirrors the shape of a life. A hexagram is a coordinate, and a scent is a scent. Knowing where you stand matters more than knowing where you should go.
He Luo Li Shu reads the numbers behind the frame you were born with. Run it alongside Zi Wei Dou Shu for the stars and BaZi for the elements, and the picture fills out.
He Luo Li Shu is a branch of I Ching study organised in the early Song dynasty by Chen Tuan, known as Master Xiyi. It converts the stems and branches of your BaZi into numbers, casts a hexagram from those numbers, and reads your life through the hexagram. BaZi works with the five elements and the ten gods. He Luo Li Shu drops straight down to the numbers underneath, compressing the frame of your chart into a single innate hexagram. The two look at different layers, so they read well side by side.
Each heavenly stem in your BaZi takes a Luo Shu number and each earthly branch takes a pair of He Tu generation numbers. Add all the odd values together and you get the Heaven number, which stands for what you were born with. Add all the even values and you get the Earth number, which stands for the environment you grew into. The Heaven hexagram sits on top and the Earth hexagram below, and together they form your innate life hexagram.
Yuan Tang is the idea that makes He Luo Li Shu distinctive. Your birth hour fixes one core line among the six lines of your hexagram, and that line becomes the coordinate the reading works from. The major luck cycles also count forward from it. Without a birth hour there is no Yuan Tang, so the innate hexagram can still be cast while the acquired hexagram and the luck cycles lose their accuracy.
The mathematics is self consistent. The same BaZi always produces the same hexagram, with no randomness anywhere. The dating and authorship of the surviving text are still debated by scholars, and no modern statistical research has tested its predictive validity. We treat it as one coordinate on the frame you were born with, useful for seeing one cross section clearly, and we hold it as a description rather than a verdict.
Casting your innate hexagram, your acquired hexagram, your Heaven and Earth numbers and your Yuan Tang line is free, and you can copy the chart data and take it with you. If you want a full reading in plain English, there is an AI reading on the site at NT$149 for the essentials and NT$599 for the full depth version. Running Zi Wei Dou Shu for the stars and BaZi for the elements alongside it gives you a rounder picture.
He Luo Li Shu turns your BaZi into numbers and casts your innate hexagram, so it reads the fixed frame you were born with. The Hour Light Time Cards are our own awareness deck of 130 cards, drawing on the I Ching, BaZi, Zi Wei Dou Shu and other traditions in a single card. You draw one in the moment, it reflects where you are right now, and it gives you one thing you can act on today. One shows the frame you arrived with, the other meets you where you are standing.