The map behind the name
What Does “Zi Wei Dou Shu” Mean?
Zi Wei refers to the Purple Enclosure associated with the celestial north and imperial symbolism in traditional Chinese astronomy. Dou Shu is commonly translated as a method of calculation through the stars. In English, the system is called Purple Star Astrology or Purple Star Calculation.
Tradition often connects the system with the Song-dynasty sage Chen Tuan. The historical record is less certain than the traditional attribution, and the method developed through multiple lineages. That matters because schools can use different rules at a few technical boundaries while still sharing the same basic palace-and-star framework.
From birth data to plate
How Is a Purple Star Chart Calculated?
A chart is generated by rules, not by choosing stars that “feel right.” The sequence below is the simplified architecture behind the calculation.
- 01
Convert the date
The Gregorian birth date is mapped to the Chinese lunisolar calendar, including lunar month, lunar day, year stem, and year branch.
- 02
Resolve the birth hour
The clock time is assigned to one of 12 two-hour earthly branches. Timezone, longitude, and optional true solar-time correction can affect a boundary.
- 03
Set the Life and Body Palaces
The lunar month and birth-hour branch establish the Life Palace and Body Palace, which anchor the plate's core structure.
- 04
Find the Five Element Bureau
The Life Palace stem-and-branch combination determines the elemental bureau used with the lunar birth day to position Zi Wei.
- 05
Place the major and supporting stars
Once Zi Wei is placed, the remaining major stars and many secondary stars follow established sequences and birth-data rules.
- 06
Layer transformations and timing
Four Transformations, decade periods, annual movement, and shorter cycles are added over the fixed natal chart.
Calculate your plate
Find Your Purple Star Chart
Enter one person's complete birth details. We will save them as a Cosmic Profile, carry the selected gender forward, and open that profile first on the Purple Star chart page.
- Complete worldwide city search
- Coordinates and historical timezone carried with the profile
- True solar-time setting visible in the calculator
The twelve rooms of the plate
What Are the 12 Palaces in Zi Wei Dou Shu?
The palaces divide the chart into concrete life domains. Their positions are fixed around the plate, but the stars occupying them are personal to the birth data.
Life Palace 命宮
Core temperament, identity, and the way a life pattern is expressed.
Siblings Palace 兄弟宮
Siblings, peers, cooperation, rivalry, and close lateral bonds.
Marriage Palace 夫妻宮
Partnership patterns, expectations, attraction, and shared life.
Children Palace 子女宮
Children, creativity, mentoring, legacy, and what is brought forth.
Wealth Palace 財帛宮
Earning style, resources, financial habits, and material priorities.
Health Palace 疾厄宮
Constitutional tendencies, stress patterns, recovery, and self-care themes.
Travel Palace 遷移宮
Life beyond familiar ground, travel, relocation, and public encounters.
Friends Palace 交友宮
Friends, collaborators, networks, teams, and the people one attracts.
Career Palace 官祿宮
Vocation, contribution, professional direction, and public responsibility.
Property Palace 田宅宮
Home, land, family environment, assets, and the inner sense of foundation.
Fortune Palace 福德宮
Inner life, contentment, spiritual resources, rest, and mental atmosphere.
Parents Palace 父母宮
Parents, elders, authority, inheritance, and formative support.
Palace names are topic headings, not isolated verdicts. For example, the Health Palace is read with connected palaces, star condition, timing, and the rest of the chart; it is not a medical diagnosis.
The principal cast
What Are the 14 Major Stars?
The 14 major stars are symbolic roles. Each one can express constructively or tensely depending on palace, brightness, combinations, and transformations.
Zi Wei
The Emperor
Centering, leadership, dignity, and the burden of responsibility.
Tian Ji
The Strategist
Intelligence, movement, planning, adaptation, and restless thought.
Tai Yang
The Sun
Visibility, generosity, principle, service, and outward vitality.
Wu Qu
The General
Discipline, execution, money sense, resolve, and practical strength.
Tian Tong
The Blessing
Ease, kindness, enjoyment, sensitivity, and a wish for harmony.
Lian Zhen
The Politician
Intensity, boundaries, charisma, ethics, and complicated desire.
Tian Fu
The Treasury
Stewardship, stability, protection, resources, and measured authority.
Tai Yin
The Moon
Reflection, receptivity, refinement, privacy, and emotional intelligence.
Tan Lang
The Desire Star
Appetite, charm, talent, experimentation, and social magnetism.
Ju Men
The Great Gate
Speech, questioning, persuasion, analysis, and verbal contention.
Tian Xiang
The Minister
Diplomacy, standards, mediation, presentation, and reliable support.
Tian Liang
The Heavenly Beam
Protection, conscience, teaching, endurance, and elder wisdom.
Qi Sha
Seven Killings
Courage, pressure, independence, decisive action, and high stakes.
Po Jun
The Breaker
Reform, disruption, risk, rebuilding, and transformation through change.
Synthesis, not keyword matching
How Is a Zi Wei Dou Shu Chart Read?
Palace + star
The palace supplies the life topic; the star supplies the style, motive, talent, pressure, or role acting there.
Brightness and company
A star's traditional strength level and its major, supportive, or challenging companions alter how freely it can act.
Four Transformations
Lu, Quan, Ke, and Ji identify where flow, power, recognition, and friction become especially active.
San Fang Si Zheng
The palace is read with its trines and opposing palace—the “three directions and four positions” that reveal the larger structure.
Life and Body Palaces
The Life Palace describes the central pattern; the Body Palace shows where that pattern becomes especially embodied and emphasized.
Natal chart + moving time
The birth plate remains fixed while decade, annual, monthly, daily, and hourly overlays activate parts of it.
Si Hua · 四化
The Four Transformations
The year's heavenly stem transforms four stars. These are dynamic modifiers—not a simple lucky/unlucky score.
Hua Lu
Flow and resources
Where opportunity, support, ease, appetite, or material flow tends to gather.
Hua Quan
Power and responsibility
Where authority, effort, control, execution, and leadership become active.
Hua Ke
Recognition and refinement
Where learning, reputation, articulation, grace, or public credit can develop.
Hua Ji
Friction and attachment
Where complications, fixation, delay, vulnerability, or repeated work asks for attention.
When the plate moves
Decade Cycles, Annual Charts, and Lunar Age
The natal plate is the fixed foundation. A Major Limit or decade cycle emphasizes one palace for roughly ten years. Annual, monthly, daily, and hourly layers then create progressively narrower timing windows. Readers compare the moving layer with the natal structure instead of replacing the birth chart.
Timing direction and starting ages are calculated from chart rules that include the year stem and gender setting. This is why the selected gender must stay attached to the profile when a plate is reopened.
Different maps, different grammar
Purple Star Astrology vs. BaZi vs. Western Astrology
| System | Primary structure | Birth data | Especially strong for |
|---|---|---|---|
| Zi Wei Dou Shu | Stars in 12 palaces, transformations, linked palace structures | Date, exact time, place, chart gender | Detailed life domains, role patterns, and layered timing |
| BaZi | Four Pillars, heavenly stems, earthly branches, Five Phases | Date, time, place | Elemental balance, ten-god relationships, luck pillars |
| Western astrology | Planets, zodiac signs, houses, aspects, angles | Date, exact time, place | Planetary psychology, aspect dynamics, transits, progressions |
These systems are complementary frameworks, not three versions of the same calculation and not a contest for a single “most accurate” chart.
The inputs that change the plate
Why Exact Birth Time and Birth City Matter
Chinese birth-hour boundaries
Zi Wei Dou Shu uses 12 two-hour branches. Crossing a boundary can move the Life Palace and change star placements.
Timezone and location
The complete birth city establishes local timezone and coordinates instead of assuming the same clock rules everywhere.
True solar time
Longitude and the equation of time can shift recorded clock time. This is most important when a birth is close to an hour boundary.
Visible school settings
Leap months, the late Rat hour, and transformation tables vary by lineage. Cosmic Oceans exposes method settings so differences can be compared.
Your chart is the beginning
See the Plate Free. Unlock the Full Reading with Premier.
Every visitor can calculate the complete visual plate. Premier opens the full interpretation beneath it: every palace, major and minor stars, brightness, transformations, trines and oppositions, structural families, detected patterns, decade timing, yearly movement, and unknown-hour comparison.
Clear answers
Purple Star Astrology FAQ
What is Purple Star Astrology?
Purple Star Astrology, or Zi Wei Dou Shu, is a traditional Chinese birth-chart system. It places 14 major stars and supporting stars into 12 life palaces using the lunar birth date, birth-hour branch, and fixed chart rules, then reads the relationships among them.
What information is needed for a Zi Wei Dou Shu chart?
Use the birth date, exact local birth time, birth city, and the gender setting used by the chart. The birth city supplies coordinates and timezone; the hour can change the Life Palace, star positions, and timing direction.
Why does my Purple Star chart show an age older than my Western age?
Zi Wei Dou Shu timing often uses Chinese lunar or nominal age. A person begins at age one, and the chart age advances with the traditional year boundary rather than only on the birthday, so it may appear one or sometimes two years higher than everyday age.
Are Purple Star Astrology and BaZi the same?
No. BaZi organizes birth information into Four Pillars of stems and branches and emphasizes Five Phase relationships. Zi Wei Dou Shu places stars in 12 palaces and reads palace structure, transformations, and timing overlays. Many practitioners use them together.
Why can two Purple Star calculators disagree?
Schools differ on leap-month handling, the early and late Rat hour, true solar-time correction, and some transformation tables. A recorded time near a Chinese two-hour boundary can also move to another hour after longitude and solar correction.
Can I calculate a Purple Star chart without a birth time?
A reliable plate needs a birth hour. If the exact time is unknown, compare all 12 Chinese birth-hour possibilities and look for stable features instead of treating one guessed hour as certain.
Is the Purple Star chart free on Cosmic Oceans?
Yes. The calculated Purple Star Plate is free and does not require an account. Premier membership unlocks the complete written reading, including palace synthesis, star details, transformations, structures, and timing interpretation.
Method and Further Reading
This guide uses the shared Zi Wei Dou Shu framework while naming school-dependent settings rather than presenting one lineage as universal. For technical study, see the open-source iztro guide to horoscope layers and its explanation of chart calculation and nominal age. For a general historical overview, see Zi Wei Dou Shu.