How to calculate the Ziwei Dou Shu chart step by step
How to Calculate the
Ziwei Dou Shu Chart
Step by Step
The most precise, beginner-friendly walkthrough of Purple Star Astrology — from your birth data to a fully constructed destiny chart.
Ziwei Dou Shu (紫微斗數), known in the West as Purple Star Astrology, is one of the most sophisticated divination systems ever created. Unlike Western astrology or the Four Pillars (BaZi), Ziwei Dou Shu uses a fixed 12-palace chart populated by 108 stars — and every single star shifts position based on your exact birth data.
“The emperor consults the stars. The scholar reads the palaces. The wise man understands that both the stars and the chart are maps — not fate itself.”
This guide teaches you exactly how to calculate your Ziwei Dou Shu chart from scratch — no software required. You will understand the logic behind every placement, not just follow instructions blindly.
What is Ziwei Dou Shu?
Ziwei Dou Shu originated during the Song Dynasty (960–1279 CE), attributed to the Taoist master Chen Tuan. It maps your life across 12 life domains called “palaces,” each governed by specific stars that determine your strengths, challenges, relationships, career, and destiny.
The system uses the Chinese Lunar Calendar — specifically your birth year, month, day, and hour — to determine the position of the Purple Star (紫微, Ziwei) and all 107 supporting stars within the 12 palaces.
Unlike sun-sign astrology, Ziwei Dou Shu gives every person a unique chart. Two people born on the same day but different hours receive completely different star configurations. This granularity makes it one of the most personalized destiny systems in the world.
What You Need Before You Begin
Gather these four pieces of information. Accuracy is everything in Ziwei Dou Shu — even one hour difference changes your chart entirely.
Your Birth Year (Lunar)
You need your birth year in the Chinese Lunar Calendar, specifically the Heavenly Stem (天干, Tiangan) and Earthly Branch (地支, Dizhi). A simple online converter converts your Gregorian birthday to its lunar equivalent instantly.
Gregorian: March 15, 1990 → Lunar Year: 庚午年 (Geng Wu) — Metal Horse Year. Stem = 庚 (Geng), Branch = 午 (Wu).
Your Lunar Birth Month
The lunar month (1st through 12th month) determines which palace becomes your Life Palace (命宮, Minggong) — the anchor of your entire chart. Note: if you were born during a leap lunar month, special rules apply.
Your Lunar Birth Day
Your birth day (1st–30th of the lunar month) directly determines the position of the Ziwei Star (紫微星) — the most important star in the entire system. Without the precise day, the whole chart shifts.
Your Birth Hour (時辰, Shichen)
Chinese astrology divides the day into 12 two-hour periods, each corresponding to one Earthly Branch. Your birth hour determines the Earthly Branch of your Life Palace.
| Time Range | Earthly Branch | Animal |
|---|---|---|
| 11 PM – 1 AM | 子 (Zi) | Rat |
| 1 AM – 3 AM | 丑 (Chou) | Ox |
| 3 AM – 5 AM | 寅 (Yin) | Tiger |
| 5 AM – 7 AM | 卯 (Mao) | Rabbit |
| 7 AM – 9 AM | 辰 (Chen) | Dragon |
| 9 AM – 11 AM | 巳 (Si) | Snake |
| 11 AM – 1 PM | 午 (Wu) | Horse |
| 1 PM – 3 PM | 未 (Wei) | Goat |
| 3 PM – 5 PM | 申 (Shen) | Monkey |
| 5 PM – 7 PM | 酉 (You) | Rooster |
| 7 PM – 9 PM | 戌 (Xu) | Dog |
| 9 PM – 11 PM | 亥 (Hai) | Pig |
The Twelve Palaces Explained
The chart is a 4×3 grid of 12 fixed palaces. Each palace governs a specific life domain. Stars that land in a palace color it with their energy — positively or negatively depending on their nature.
The Life Palace (命宮) is always your starting point. Once you fix its position in the grid, all 11 other palaces fall into place counter-clockwise around it.
Step-by-Step Calculation Guide
Follow these steps in exact order. Each step builds on the previous one. Do not skip ahead.
Convert to the Lunar Calendar
Convert your Gregorian birth date to the Chinese Lunar Calendar. Use a reliable converter — note the lunar year’s Heavenly Stem, Earthly Branch, lunar month number, and lunar day number. Write all four down before proceeding.
Determine Your Birth Hour Branch
Using the hour table in Section 02, identify the Earthly Branch for your birth time. This is your Hour Branch (時支). Store it — you need it in Step 3.
Locate the Life Palace (命宮)
The Life Palace position uses your lunar birth month and hour branch. Apply this formula:
Count forward by your lunar month number.
Then count backward by your hour branch number.
The resulting branch = your Life Palace position.
In practice: if born in the 3rd lunar month during the Zi (子) hour, start at Yin, move forward 3 to reach Si (巳), then move backward 1 to reach Chen (辰). Life Palace = Chen palace.
Assign Earthly Branches to All 12 Palaces
Once you know your Life Palace branch, assign all 12 Earthly Branches to the 12 palace positions going counter-clockwise. The fixed chart grid looks like this: the top row runs Hai–Zi–Chou–Yin (right to left), the right column runs Yin–Mao–Chen (top to bottom), and so on around the grid.
The Earthly Branches always follow the fixed sequence: 子丑寅卯辰巳午未申酉戌亥 — counter-clockwise around the chart grid. Your Life Palace branch simply determines where this sequence starts.
Assign the Five Element (五行) to Your Chart
Your birth year’s Heavenly Stem and the Life Palace’s Earthly Branch together determine the Five Element (五行局, Wuxing Ju) of your chart. There are five types: Water 2, Wood 3, Metal 4, Earth 5, Fire 6. This number tells you how many days to count when placing the Ziwei Star.
| Five Element Type | Chinese | Count Days By |
|---|---|---|
| Water Bureau | 水二局 | Groups of 2 |
| Wood Bureau | 木三局 | Groups of 3 |
| Metal Bureau | 金四局 | Groups of 4 |
| Earth Bureau | 土五局 | Groups of 5 |
| Fire Bureau | 火六局 | Groups of 6 |
Place the Ziwei Star (紫微星)
This is the most important calculation. Use your lunar birth day and your Five Element Bureau number to locate the Ziwei Star’s palace.
The quotient = steps forward from Yin (寅).
The remainder determines adjustment.
If remainder = 0: the star sits at the counted position.
If remainder ≠ 0: add the Bureau number minus the remainder.
Example: Born on day 14, Wood Bureau (3). 14 ÷ 3 = 4 remainder 2. Count 4 steps forward from Yin = Wu (午). Remainder is 2, not 0, so continue: 3−2=1 step further → Wei (未). Ziwei Star = Wei palace.
Place the 13 Major Stars of the Emperor Group
Once you place Ziwei, the other 13 stars in his “Emperor Group” (天府系 and 紫微系) fall into fixed positions relative to him. These stars always travel together and maintain the same relative distances from Ziwei.
| Star | Chinese | Position Relative to Ziwei |
|---|---|---|
| Tianji | 天機 | 1 palace before Ziwei |
| Taiyang | 太陽 | 2 palaces before |
| Wuqu | 武曲 | 3 palaces before |
| Tiantong | 天同 | 4 palaces before |
| Lianzhen | 廉貞 | 5 palaces before |
Locate the Tianfu Star (天府星) — The Empress
Tianfu is the second most important star and leads the Empress Group (天府系). Find Tianfu by counting from Ziwei: move in the opposite direction the same number of palaces as Ziwei is from Yin — essentially mirroring across the chart.
Once Tianfu is placed, her satellite stars (Taiyin, Tanlang, Jumen, Tianliang, Qisha, Pojun) fall at fixed intervals from her palace.
Place the Year Stars (年系星)
A group of stars is placed based on your birth year’s Earthly Branch. These include Lucun (祿存), Qingyang (擎羊), Tuoluo (陀羅), Tiankui (天魁), Tianyue (天鉞), and others. Each has a fixed lookup table based on the year branch.
Qingyang and Tuoluo are malefic stars — they create obstacles wherever they land. Knowing their position is essential for identifying life challenges.
Place the Month Stars (月系星)
Stars like Zuofu (左輔) and Youbi (右弼) — the two helpers — are placed using your lunar birth month. Zuofu starts at Chen (辰) palace for month 1 and counts forward one per month. Youbi starts at Xu (戌) and counts backward.
Place the Day & Hour Stars
Certain stars depend on your exact birth day (e.g., Tiancai 天才, Tianshou 天壽) and your birth hour (e.g., Wenqu 文曲, Wenchang 文昌 — the literary stars). Wenchang starts at Xu (戌) for the Zi hour and counts backward one palace per hour branch.
Assign the Four Transformations (四化)
The Four Transformations — Hua Lu (化祿 Prosperity), Hua Quan (化權 Power), Hua Ke (化科 Fame), and Hua Ji (化忌 Obstruction) — are assigned based on your birth year’s Heavenly Stem. Each stem activates four specific stars into transformation mode.
A Hua Ji (化忌) landing in your Wealth Palace warns of financial leakage. A Hua Lu in your Career Palace signals natural career luck. The Transformations are the most powerful overlay on any chart.
Set Up the Decade Luck Cycles (大限, Daxian)
Your life unfolds in 10-year Luck Cycles. The starting age of your first cycle depends on your Five Element Bureau. Water Bureau starts at age 2; Wood at 3; Metal at 4; Earth at 5; Fire at 6. Each cycle activates one palace as your dominant life theme for a decade.
The direction (forward or backward through palaces) depends on your birth year’s Yin-Yang polarity. Male born in Yang year = forward. Male born in Yin year = backward. Female reverses these rules.
Read the Annual Flow (流年, Liunian)
On top of your natal chart and decade cycles, each calendar year activates a specific palace as the Annual Flow (流年). To find your current Annual Flow palace, take the current year’s Earthly Branch and locate which palace in your chart carries that branch. That palace becomes the lens for this year’s events.
Triple-layer reading — natal chart + decade cycle + annual flow — gives the most accurate predictions. A single afflicted star means little; three layers of affliction pointing to the same palace signals a genuine crisis window.
The Main Stars & Their Core Meanings
There are 108 stars in total, but 14 major stars dominate chart reading. Mastering these first gives you 80% of the chart’s meaning.
| Star Name | Chinese | Element | Core Energy |
|---|---|---|---|
| Ziwei | 紫微 | Earth (+) | Authority, dignity, leadership, emperor energy |
| Tianji | 天機 | Wood (+) | Intelligence, strategy, change, siblings |
| Taiyang | 太陽 | Fire (+) | Fame, generosity, father, public life |
| Wuqu | 武曲 | Metal (+) | Finance, willpower, military, direct action |
| Tiantong | 天同 | Water (+) | Enjoyment, blessings, easy life, Taoist |
| Lianzhen | 廉貞 | Fire (−) | Prison, desire, loyalty, political intrigue |
| Tianfu | 天府 | Earth (+) | Stability, wealth, empress, preservation |
| Taiyin | 太陰 | Water (+) | Wealth, beauty, femininity, mother, art |
| Tanlang | 貪狼 | Wood/Water | Desire, talent, romance, social charm |
| Jumen | 巨門 | Water (−) | Disputes, speech, mouth, verbal skill |
| Tianliang | 天梁 | Earth (+) | Protection, elders, medicine, virtue |
| Qisha | 七殺 | Metal/Fire | Courage, aggression, breaking limits, warrior |
| Pojun | 破軍 | Water (−) | Destruction, renewal, pioneering, extremes |
| Lucun | 祿存 | Earth (+) | Wealth retention, savings, protection |
How to Read Your Completed Chart
A completed chart is not read palace by palace in isolation. You read it as a dynamic system of interactions. Here is the professional reading framework:
Start with the Life Palace (命宮)
Identify all stars in the Life Palace. This reveals your core personality, life theme, and natural strengths. A Life Palace with Ziwei indicates a person built for leadership. A Life Palace with Pojun signals a life of constant transformation.
Check the Three Vitals: Career, Wealth & Relationships
Always read palaces 5 (Wealth), 9 (Career), and 3 (Spouse) next. These three palaces answer 80% of the questions most people actually ask about their lives.
Analyze Opposite Palaces
Every palace has an opposite palace that “shines” into it. Your Life Palace is directly influenced by the Travel Palace (Palace 7) opposite it. Reading opposite palaces reveals hidden tensions and external pressures acting on each life domain.
Apply the Four Transformations
Overlay the Hua Lu, Hua Quan, Hua Ke, and Hua Ji onto the chart. Wherever Hua Ji (obstruction) lands, that palace faces the most significant challenges. Wherever Hua Lu lands, that area flows naturally and attracts good fortune.
Frequently Asked Questions
Your Stars Are Already Written.
Now You Can Read Them.
You now hold the complete framework to calculate and begin reading a Ziwei Dou Shu chart. The stars do not control you — they illuminate the landscape of your life so you can navigate it with wisdom.
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