Kua Number 卦命
Guà Mìng · A personal number from one to nine used to pick favourable directions.
What it means
The Kua number, also written Gua, is a single digit derived from a birth year and sex in the Eight Mansions school of feng shui. It assigns each person to one of eight trigram groups — four "east group" and four "west group" — and each group has four favourable and four unfavourable compass directions for sleeping, sitting and facing.
Why it matters
Eight Mansions and Flying Stars are two different systems that both use the same compass, and mixing them produces contradictions. Kua is personal and fixed for life; Flying Stars are annual and apply to a building. It is also worth knowing that Kua formulas differ between sources on how to treat births before Lichun and how to handle the number five, so results vary by practitioner.
Where this site uses it
This site publishes the annual Flying Star chart, which applies to a space rather than a person, and does not calculate Kua numbers, because the competing formulas would need a choice this site is not in a position to defend.