The 8 Mansions Theory is a part of the Compass School Feng Shui which is used to identify your good (auspicious) and bad (inauspicious) directions based on your lunar birth year and gender. Using your lunar birth year and gender, you can calculate your Kua number as explained below:

The first thing to do is to check your birth date against the Chinese calendar. Make sure that you are using the correct Chinese year of birth. If you are born before the first week of February, you might have to use the previous year as your point of reference. After you have established your Chinese year of birth, you can use the following formula:

For Males:
Using your Chinese year of birth, add the last two digits together. Reduce it to a single digit number and subtract this number from 10. The final answer is your personal Kua Number.

Example:

Year of birth = 1960.
6 + 0 = 6
10 – 6 = 4
So, men born in 1960, your Kua Number is 4.

For Females:
Determine your Chinese year of birth, then add the last two digits together.  Reduce it to a single digit number and add 5 to the resulting number.  The final answer is your personal Kua Number.

Example :

Year of birth = 1969
6 + 9 = 15, to reduce to a single digit, 1+5=6
6 + 5 = 11,
1 + 1 = 2
So, women born in 1969, your Kua Number is 2

Your Kua number at a Glance

Year of Birth (Use previous year if you were born before Chinese New Year)	Male Kua #	Female Kua #
1973, 1982, 1991, 2000, 2009, 2018	9	6
1974, 1983, 1992, 2001, 2010, 2019	8	7
1975, 1984, 1993, 2002, 2011, 2020	7	8
1976, 1985, 1994, 2003, 2012, 2021	6	9
1977, 1986, 1995, 2004, 2013, 2022	5	1
1978, 1987, 1996, 2005, 2014, 2023	4	2
1979, 1988, 1997, 2006, 2015, 2024	3	3
1980, 1989, 1998, 2007, 2016, 2025	2	4
1981, 1990, 1999, 2008, 2017, 2026	1	5

Once you have identified your Kua number, you can then check out your good and bad directions here.