The Kua Number (also called the Personal Number or Ming Gua) is the foundation of the Eight Mansions school of Feng Shui. It is derived from your birth year and gender, and it tells you which four of the eight directions are personally auspicious.
Step 1 — The year factor
Add the last two digits of your birth year and reduce to a single digit. Example: 1985 → 8+5 = 13 → 1+3 = 4.
Step 2 — Apply the gender rule
Born 19xx: men subtract the factor from 10; women add 5.
Born 20xx: men subtract the factor from 9; women add 6. Reduce any two-digit result again.
Step 3 — The Kua 5 rule
If the result is 5, the common convention substitutes Kua 2 for men and Kua 8 for women (both West Group numbers).
Our calculator also shows the year boundary used (Gregorian vs Li Chun) so you always know exactly which method was applied. Kua 1, 3, 4 and 9 belong to the East Group; Kua 2, 6, 7 and 8 to the West Group.
Remember: Kua Number guidance is a traditional Feng Shui practice, useful as a design preference rather than a guarantee.