The short answer
To find your KUA number, use your birth year and your gender. Reduce the last two digits of the year to a single digit, then apply one of four formulas: men subtract the digit from 10 (or 9, for births in 2000 or later), and women add 5 (or 6). A result of 5 becomes 2 for men and 8 for women. Check the early-February date first, because a birthday in early February can fall in the previous solar year.
What you need before you calculate
- Your birth year and your birth date.
- Your gender, because the formula is different for men and women.
- The Li Chun date for your birth year, if your birthday is in January or early February.
Step 1: Check the Li Chun date
The Chinese solar year begins at Li Chun, around 3, 4 or 5 February, depending on the year. A birthday before that date counts as the previous year. Look up the exact date for your birth year before you go on. On the day itself, the exact time can matter, so check a solar-calendar table if your birthday is close to Li Chun.
Step 2: Add the last two digits and reduce
Add the last two digits of the year together. If the total has two digits, add them again. Call the single digit you end up with d.
Step 3: Apply the formula for your gender
- Born before 2000: men subtract d from 10. Women add 5 to d.
- Born in 2000 or later: men subtract d from 9. Women add 6 to d.
- Result of 5: men become kua 2, women become kua 8.
- Result of 0 for a man born in 2000 or later: this counts as kua 9.
Worked examples
- A man born in 1981: 8 + 1 = 9. Then 10 − 9 = 1. Kua 1.
- A woman born in 1986: 8 + 6 = 14, then 1 + 4 = 5. Then 5 + 5 = 10, then 1 + 0 = 1. Kua 1.
- A woman born in 1975: 7 + 5 = 12, then 1 + 2 = 3. Then 3 + 5 = 8. Kua 8.
- A man born in 1975: 7 + 5 = 12, then 1 + 2 = 3. Then 10 − 3 = 7. Kua 7.
The last two examples show why gender matters. Two people born in the same year can have different kua numbers.
Not sure? Use the lookup table
If you have worked out d, the kua number guide has a lookup table that gives your number for each gender and each era. It saves the arithmetic and makes it easy to check your working.
Once you have your number, the next step is to find your directions. The how to know your feng shui direction guide shows how to read them. The Eight Mansions overview explains the system behind them.
These are traditional guidelines, not scientific findings.