Your Kua number, and why it splits households
Four good directions, four bad ones, and a real problem when two people in one bed disagree.
2 min read · Published 16 August 2026
Before the detail
Your Kua number (卦數) is a figure from 1 to 9, excluding 5, worked out from your lunar birth year and your sex, and used in Eight Mansions feng shui to give you four favourable and four unfavourable compass directions. Numbers 1, 3, 4 and 9 are the East group; 2, 6, 7 and 8 are the West group; and the two groups' favourable directions do not overlap at all.
How it is calculated
Reduce the digits of your lunar birth year to one figure. Men born before 2000 subtract it from 10; from 2000, from 9. Women born before 2000 add 5; from 2000, add 6. A result of 5 becomes 2 for men and 8 for women, since the centre of the Lo Shu square has no direction. The year is the lunar year, so January births belong to the previous year.
The two groups
| Group | Kua numbers | Favourable directions |
|---|---|---|
| East | 1, 3, 4, 9 | North, East, Southeast, South |
| West | 2, 6, 7, 8 | West, Northwest, Northeast, Southwest |
The two sets are complements. No direction is favourable to both groups.
Kua numbers split households over a bedroom orientation, and I would side with whoever sleeps better.
That is why households split
A couple with one East and one West person cannot find a front door that suits both. The traditional remedy is room by room: give the person the facing suits least the bedroom that faces their own best direction. Our home calculator says when residents' charts disagree.
What the four directions are supposed to do
生氣 Sheng Qi for vitality; 天醫 Tian Yi for health; 延年 Yan Nian for relationships; 伏位 Fu Wei for stability. None of it has been demonstrated, and it costs nothing to angle a desk.
Questions people ask
- How do I calculate my Kua number?
- Reduce the digits of your lunar birth year to one figure. Men born before 2000 subtract it from 10, from 2000 from 9. Women born before 2000 add 5, from 2000 add 6. A result of 5 becomes 2 for men and 8 for women.
- Why does my Kua number differ between websites?
- Almost always the lunar year. Anyone born in January or early February belongs to the previous lunar year, and a calculator using the calendar year gives the wrong number and the wrong four directions.
- Can two people in one house have different favourable directions?
- Yes, and if they are in different groups their favourable directions do not overlap at all. The traditional approach applies directions room by room.
Lily Lau