Zi Wei Dou Shu Calculator
Cast your Purple Star Astrology chart free from your exact birth time — all twelve palaces and fourteen major stars. Then read what it actually means, in plain English.
No account · no email · takes about 30 seconds
Most calculators stop at the chart
You enter your birth details, a grid of twelve boxes appears, and every box is filled with terms nobody explained — 化忌, 三方四正, 庙旺利陷. You end up searching each one separately, or you close the tab.
Kavira shows the same chart, with each star named three ways — Chinese, pinyin and a plain-English archetype — and then tells you what the combination actually means for how you think, work and love. No jargon, no homework.
What you get
- Your full twelve-palace chart (命宫, 财帛, 官禄, 夫妻 and the rest), rendered instantly
- The fourteen major stars placed by your exact birth hour, with brightness and the Four Transformations
- A free reading: who you are, the pattern you keep hitting, and what this stretch of life is asking of you
- Three free questions to an AI astrologer that has your actual chart in front of it
How the chart is calculated
Four steps happen between your birth details and the grid you see. Your Gregorian birthday is converted to the lunar date the system needs. Your clock time is corrected to true local solar time using the longitude of your birth city, which is why the city is required rather than optional. That corrected time is mapped to one of the twelve two-hour periods. Finally the Life Palace is placed from the lunar month and that period, and the remaining eleven palaces and the fourteen major stars follow from it.
The correction step is the one most calculators skip. Clock time is a political convention — a whole time zone shares one clock while the sun moves across it — so a birth in the far west of a time zone can sit fifteen or more minutes away from its true solar time, which is enough to change the period and therefore the entire chart.
New to the system?
If the chart raises more questions than it answers, these explain the parts that matter:
Already have a chart?
Look your Life Palace stars up directly — by Chinese name or pinyin, whichever your chart uses:
See all Life Palace readings →
Questions
What is a Zi Wei Dou Shu calculator?
You will see the name written several ways — Zi Wei Dou Shu, ziweidoushu, Ziwei Doushu, or 紫微斗数. They are all the same system, also called Purple Star Astrology. It builds a natal chart of twelve palaces from your exact birth date, hour and place. A calculator does that maths for you: it places the fourteen major stars — Zi Wei 紫微, Tian Ji 天机, Tai Yang 太阳, Wu Qu 武曲, Tian Tong 天同, Lian Zhen 廉贞, Tian Fu 天府, Tai Yin 太阴, Tan Lang 贪狼, Ju Men 巨门, Tian Xiang 天相, Tian Liang 天梁, Qi Sha 七杀 and Po Jun 破军 — into the palace each one governs.
Why does my birth time matter so much?
Because the whole chart pivots on it. The hour pillar changes on the odd hours, and your true solar time shifts with the longitude of your birthplace — so two people born twenty minutes apart in the same city can get completely different charts. A birth year alone (the Chinese zodiac) cannot do this.
Is Zi Wei Dou Shu the same as BaZi?
No. BaZi (八字, Four Pillars) reads your destiny through the elements of four time pillars. Zi Wei Dou Shu maps it through space — which star sits in which of your twelve palaces. They are the two major systems of Chinese natal astrology and practitioners often read both.
I already have a chart from another site. Can I just look up what my stars mean?
Yes. Every Life Palace star combination has its own page here, listed by Chinese name and pinyin — so if your chart says 天同巨门 or "Tian Tong Ju Men", you can go straight to that reading without casting anything.
Do I need an account?
No. No sign-up, no email. Enter your birth details, get your chart and your reading free.
What do I need to enter?
Your birth date, your birth time, your birth city and your sex as recorded at birth. All four are required. The city is used to correct clock time to true local solar time, and sex is used because it determines the direction the decade cycles (大限) run.
Do I enter my lunar birthday or my normal one?
Your normal, everyday birthday — the Gregorian date on your documents. The conversion to the lunar calendar that Zi Wei Dou Shu needs is done for you.
What if my birth time is on a two-hour boundary?
Then the birth city matters even more. Zi Wei Dou Shu periods change at 23:00, 01:00, 03:00 and so on, and correcting clock time to true solar time can move you across a boundary by ten or twenty minutes. If your recorded time is within about half an hour of a boundary, treat the resulting chart with some caution.
Is the Zi Wei Dou Shu calculator free?
Yes. Casting the chart and the opening reading are free, with no account and no email. Continuing the conversation beyond the free questions is the only paid part.
Your chart is 30 seconds away — free, no account.
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