Casting a BaZi chart online takes seconds, but many people then face a screen full of characters and jargon. This guide covers what to prepare and what each section of the result means.
What you need before casting
Birth date
Gregorian or lunar both work. With lunar dates, mark leap months correctly, or the month pillar will be wrong.
Birth time
The hour pillar needs the double-hour (shichen); each lasts two hours, e.g. Zi is roughly 23:00–01:00. If you only know a rough time, the hour pillar may be off; if you don't know it at all, read just the year, month and day pillars.
Birthplace
Used to convert to true solar time. China uses Beijing time everywhere, but the sun's real position varies, especially in the west. This matters if you were born near the boundary of a double-hour.
Sex
It doesn't change the four pillars but sets whether luck pillars run forward or backward.
Reading the result
Four pillars, eight characters
Year, month, day and hour pillars, each a heavenly stem above an earthly branch: eight characters in all. The year changes at Lichun and months change at solar terms, not lunar month starts.
Day Master
The day stem represents you; almost everything else is read relative to it.
Hidden stems
Each branch "hides" one to three stems — Yin hides Jia, Bing and Wu. They enrich the elemental picture and matter for strength judgments.
Ten Gods
Labels like Companion, Direct Wealth or Seven Killings mark ten relationships to the Day Master, derived from element cycles and yin/yang. They are the basic "language" of a chart.
Na Yin
A separate system assigning an element to each pair of the sixty cycle, e.g. "Jia Zi, Yi Chou — Gold in the Sea". In Ziping BaZi it is usually a secondary reference.
Luck pillars and annual pillars
Ten-year luck pillars with their starting age, plus each year's stem-branch — the time dimension of the chart.
Symbolic stars
Some charts list stars like Heavenly Noble, Peach Blossom or Travel Horse. Their sources are mixed and schools differ widely; beginners can simply learn the names.
Common mistakes
- Leap lunar month not marked, giving a wrong month pillar.
- Born on a solar-term day — a few hours can mean a different month pillar.
- Born 23:00–00:00 — "early" vs. "late" Zi hour rules differ between tools.
- Born in summer 1986–1991 in China — daylight saving time may have put clocks an hour ahead.
Casting is only the start
Casting follows fixed rules, so the same input gives the same pillars. Interpretation is where schools differ. Treat the chart as a doorway into traditional calendars and Five Elements culture.
This article is for cultural reference only and is not advice for any decision.