Cast your Tử Vi (Purple Star Astrology) chart
Cast your Tử Vi chart from your birth date, birth hour and sex; the page converts to the lunar calendar and places the stars in the twelve palaces. You get the full chart, a five-line summary of personality, work, money, love and the current year, and a reading for each palace.
Where this comes from
The star-placing rules of Tử Vi Đẩu Số, in the version most used in Vietnam (Tử Vi Đẩu Số Tân Biên). Tradition credits the system to Chen Tuan of the Song dynasty; modern research does not treat that as established. The lunar date and stems and branches are calendar computations; star placement, the Four Transformations and star strength are the school's lookup rules.
This tool is part of Tử Vi (Purple Star astrology). See every tool and article on Tử Vi (Purple Star astrology).
Classical allusion
“Cư trần lạc đạo thả tuỳ duyên, cơ tắc xan hề khốn tắc miên.”
Translation: Dwell in the world, delight in the Way, and follow what comes: eat when hungry, sleep when tired.
Trần Nhân Tông · Rhapsody on Dwelling in the World and Delighting in the Way
Where the schools differ
When the day turns over
7 more
The Four Transformations for the stems Canh, Tân and Nhâm
Minor stars not placed
Grouping the major star in Mệnh into three sets
Thiên Khôi and Thiên Việt for the stem Canh
Direction of the Tràng Sinh cycle
Where the ten-year periods start
Where the monthly periods start
What no one has shown
No study has shown that star positions on the chart correspond to a person's character or life. The machine only guarantees that the school's rules are applied correctly.
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What is a Tử Vi chart, and where should you start reading?
Tử Vi Đẩu Số is an old Chinese way of reading a life, traditionally credited to Chen Tuan of the Song dynasty and long established in Vietnam. The chart is a grid of twelve boxes called palaces. Each palace covers one part of life: who you are, money, work, marriage, home.
To build the chart, the page converts your Gregorian birth date and hour to the lunar calendar, finds the Life palace from the birth month and hour, then places the 14 main stars and many minor ones by fixed rules. The same birth date, hour and sex always give the same chart.
The birth hour matters most. Being off by one double hour (two clock hours) moves the Life palace to another box and changes most of the reading. If you are unsure of the hour, treat the chart as loose reference.
Born between 23:00 and midnight: this chart uses the lunar date of exactly the Gregorian date you enter. Some books count a birth from 23:00 as the next day; to follow them, enter the next day. The site's Bát Tự chart turns the day at 23:00, so the two tools can show different days.
The Four Transformations (Lộc, Quyền, Khoa, Kỵ) are four marks placed on four stars by the birth-year stem. The stems Canh, Tân and Nhâm have several versions across books. For Canh, the page uses Thiên Đồng as Hóa Khoa and Thái Âm as Hóa Kỵ, and lists the other two versions under the chart.
The easiest order: the five-line summary, then the Life palace with the one opposite it, then whichever palace you care about. The ten-year periods show which palace the current decade passes through; the yearly section shows which palace the year falls in.
| Palace | What it covers |
|---|---|
| Life (Mệnh) | Who you are, personality |
| Parents | Parents, elders |
| Fortune | Inner life, the wider family |
| Property | Home and land |
| Career | Work and career |
| Friends | Friends, colleagues, subordinates |
| Travel | Going away, the world outside |
| Health | The body (in the books' terms) |
| Wealth | Money |
| Children | Children |
| Spouse | Marriage and love |
| Siblings | Brothers and sisters |
Frequently asked questions
What do I need to enter for a Tử Vi chart?
Your Gregorian birth date, your birth hour as a double hour (Tý, Sửu...) and your sex. Your name only labels the chart; it does not move any star.
What if I do not know my exact birth hour?
You can still cast it, but one double hour off moves the Life palace and the reading with it. You can try the two neighbouring double hours and compare.
I was born at 23:30. Which date should I enter?
This chart uses the date exactly as entered. If you follow books that count a birth from 23:00 as the next day, enter the next day.
How is Tử Vi different from Western astrology?
Western astrology uses where the planets actually were at birth. Tử Vi uses symbolic stars placed by rules from the lunar birth date and hour, not from the real sky.
Should I worry about Hóa Kỵ on my chart?
Every chart has one Hóa Kỵ from the birth year. Tử Vi readers usually take it as a spot where things tend to snag and need care, not a warning of something bad that will surely happen.
Is a palace with no main star a bad sign?
No. Tử Vi reads such a palace through the stars in the opposite palace, and the quick summary does the same.
Which book does the Four Transformations table follow?
Mostly the version common in Vietnam (Tử Vi Đẩu Số Tân Biên). For Canh alone, the page uses Thiên Đồng as Hóa Khoa and Thái Âm as Hóa Kỵ, after Huyền Vi, Thiên Lương and Việt Viêm Tử; Tân Biên and the Tử Vi Đẩu Số Toàn Thư give Thái Âm as Hóa Khoa and Thiên Đồng as Hóa Kỵ, and some books give Thiên Phủ as Hóa Khoa and Thiên Đồng as Hóa Kỵ. Tân and Nhâm have variants too.