BaZi Calculator: your Four Pillars of Destiny

Questions

What is BaZi?

BaZi (八字, "eight characters") is a Chinese system that describes a person through the year, month, day and hour of birth. Each of the four pillars is written as a Heavenly Stem above an Earthly Branch, giving eight characters, and the reading looks at how their five elements support or restrain one another.

Are BaZi, the Four Pillars of Destiny and Saju the same thing?

Yes. Four Pillars of Destiny is the English name for BaZi, and Saju (사주, from 四柱, "four pillars") is the Korean name for the same system. Japanese practice calls it Shichū Suimei 四柱推命. The pillars are calculated the same way in each.

Why is my BaZi year different from my Chinese zodiac year?

The popular Chinese zodiac usually changes animal at the lunar new year, which moves between late January and mid February. BaZi changes year at Li Chun 立春, around 4 February. If you were born between those two dates, your BaZi year pillar belongs to the neighbouring year.

What if I do not know my birth time?

Tick "I don't know my birth time" and the calculator shows the year, month and day pillars, which are six of the eight characters. If a solar term falls on your birth date, it warns you that the month pillar depends on the time.

How does the calculator judge Day Master strength?

It adds up how much of the chart supports the Day Master: characters of the same element, and of the element that produces it. The month branch counts most (30 of 100 points), then the day and hour branches, then the other stems and the year branch, and each branch shares its points among its hidden stems. Fifty or more reads as strong. It is our documented score; practitioners also weigh the season and the chart pattern, so treat a score between 40 and 60 as open.

What is the seasonal Useful God?

The Qiong Tong Bao Jian 窮通寶鑑, a Qing-dynasty classic, lists for each Day Master in each month the stems that balance the season: warmth in winter, water in summer, and so on. Your chart page shows the entry for your birth month. It is one of two common ways to choose a Useful God; the other balances strength, which the chart shows as balancing elements.

Does the calculator use true solar time?

No. It uses your local clock time and the time zone you choose. True solar time adjusts the clock for your longitude and the time of year, and it only changes the result when a birth is close to the edge of a two-hour block.

Is my birth data stored?

Yes, so that your chart has a link you can come back to. A chart made without an account holds only the birth date, time, time zone and gender, with no name or email. If you sign in, your charts are kept under My charts.

How is BaZi different from Purple Star Astrology?

BaZi reads the balance of five elements across eight characters taken from the solar calendar. Purple Star Astrology (Zi Wei Dou Shu 紫微斗數) places over 100 stars in 12 life palaces using the lunar calendar. They are separate systems and often describe the same person differently.