Zi Wei Dou Shu Calculator

Zi Wei Dou Shu (紫微斗数, "Purple Star Astrology") is a Chinese birth-chart system that arranges more than a hundred stars across twelve palaces. Where BaZi reads the balance of five elements in eight characters, Zi Wei describes life areas — self, siblings, spouse, children, wealth, health, travel, friends, career, property, fortune and parents — through the stars that fall in each palace.

This calculator converts your birth date to the lunar calendar, locates the life palace (命宫) and body palace (身宫) from the lunar month and birth hour, determines the five-element bureau (五行局) and then places the fourteen major stars, the auxiliary and minor stars, their brightness and the Four Transformations (四化) of the birth year. Decade periods (大限) are listed with their palaces and ages.

The rule set is fixed and stated on the page, so the same input always produces the same chart. Where schools differ — for example on leap months or on the boundary of the 子 hour — the convention used is shown with the result.

1. Enter the birth date in the Gregorian calendar; the tool converts it to the lunar date.
2. Enter the birth time and city. The hour decides the life palace, so accuracy matters more than in BaZi.
3. Choose the gender option, which sets the direction of decade periods.
4. Calculate. The twelve palaces appear in the traditional square layout.
5. Click any palace to see its stars, brightness and transformations.
6. Use the decade list to find the palace governing the current period.

The major stars in the life palace (命宫) set the main theme of the chart. Read them together with the three palaces in harmony and opposition — wealth, career and travel (三方四正) — which classical texts treat as one unit.

Each star has a brightness (庙, 旺, 得, 利, 平, 不, 陷) depending on the palace branch. A bright star expresses its qualities more fully. The Four Transformations — 化禄, 化权, 化科, 化忌 — mark where the year stem adds emphasis, opportunity or friction.

Each decade period (大限) moves the reference palace. Read the stars of the decade palace and its own three-and-four as the theme of those ten years.

• Without a birth time the chart cannot be built, because the life palace depends on the hour; the tool asks for at least an hour range.
• If the date falls in a lunar leap month, the result notes how it was treated.
• Invalid dates (e.g. 30 February) are rejected with a message rather than silently corrected.
• Printing hides navigation and interactive controls,, so the board and its explanation print cleanly without the menus.
• If JavaScript is disabled, this explanatory text still loads; the interactive board needs JavaScript.

• Hour PillarThe hour pillar covers one of twelve two-hour periods (时辰), starting with 子 at 23:00–01:00.
• True Solar TimeTrue solar time is clock time corrected for longitude (four minutes per degree from the zone meridian) and the equation of time (up to about ±16 minutes over the year).
• Sexagenary CyclePairing the ten stems with the twelve branches in order (yang with yang, yin with yin) gives sixty combinations, from 甲子 to 癸亥.
• Four PillarsThe Four Pillars are the year, month, day and hour of birth, each written as a heavenly stem over an earthly branch.

The Zi Wei Dou Shu Calculator uses one fixed rule set, named on this page, so the same input always gives the same result. Traditional methods often have several schools; mixing their rules inside one chart produces boards that no textbook would recognise, which is why only one complete preset is offered.

The engine is tested against worked examples from standard references, and every intermediate value is displayed. If your book shows something different, compare the intermediate values first — the difference is almost always a convention, such as the day boundary or how a leap month or solar-term transition is handled. Calendar data comes from an astronomical library that computes solar terms and lunar months to the minute, so differences of a day or more between sources usually point to a convention rather than an error in the underlying astronomy.

Whether you are new to the Zi Wei Dou Shu Calculator or checking work from a class, the same routine helps you learn faster and avoid common errors:

1. Record the input exactly: date, time, place and, for divination, the question in one sentence.
2. Generate the board and save or print it before interpreting anything.
3. Identify the one or two fields that matter most for the question, using the steps above.
4. Write a short provisional reading and the reason for it.
5. Revisit the notes later and compare with what actually happened, adjusting your understanding of the symbols — not the board.

Treat the Zi Wei Dou Shu Calculator as a structured way to think about a question, not as an instruction. Write down the question and the result, and return to them later; many practitioners keep a journal of casts to learn how the symbols behave over time. For decisions involving health, money or law, consult a qualified professional. The tool is free, needs no account, and does not store your question unless you choose to save it.

The fastest way to understand Zi Wei Dou Shu Calculator is to look at real charts rather than memorise rules. Enter a birth date, time and city in the BaZi Calculator, then locate where Zi Wei Dou Shu Calculator appears: in a visible stem, hidden inside a branch, in the current luck pillar or in this year's annual pillar. Note the position, because the year pillar is usually read as background and early life, the month pillar as environment and career setting, the day pillar as the self and close partner, and the hour pillar as later life and output.

• Compare two or three charts where Zi Wei Dou Shu Calculator is prominent and two where it is absent; write down what differs in the overall balance.
• Check the month branch first: seasonal strength changes how much any factor matters.
• Use the hidden-stems and Ten Gods tables in the calculator output instead of guessing.
• Treat single factors as clues, never as verdicts; classical texts always weigh the whole chart.

Different schools describe Zi Wei Dou Shu Calculator with slightly different emphasis. This site follows widely used conventions (solar-term months, true solar time optional, Zi hour setting configurable) and states them openly so you can compare results with a book or another calculator.

See the Zi Wei Dou Shu Calculator FAQ, the glossary and the comparisons for how this method relates to BaZi and other systems.

BaZi is a traditional cultural system. This page explains how the symbols are defined and read; it does not make scientific claims or predictions about your health, money or relationships.