Hi!

It is based on your birth information.
There are a few books out there that do tell you how.
I like "The Principles of Feng Shui" by Master Larry Sang.
Its not full of pretty pictures like most Feng Shui books, but the content is good - more academic.I found it at his school website:
www.amfengshui.com

also amazon has it....

have fun!
serene-dipity

Dear neonnymph,

Send the following information for your personal element.
1.Name
2.Date of birth.
3.Birth hour.
4.Gender.(Male or Female)

Regards,
Mukhtar.

There are two birth elements. One is the year you were born. This determines your Ming Gua which is what you use to see how well you match up with the house/office that you live/work in.

The other is for your personal Astrology chart. That involves knowing the day and month you were born. In order to do a proper chart, your hour, day, month and year of birth are required; this natal chart gives you your strengths and weaknesses; as well, it shows the changing qi which occurs every ten years and which influences your life. From this chart, you would have both an element and an animal (i.e., Wood Monkey); each animal consists of one-to-three-three elements. The strength of each element various through the year. Wood is strong in Spring; Metal is strong in the Fall, etc.. At other times, the elements are very weak. All of this is assessed in a chart.

This is the formula to determine your Ming Gua:

Add the digits of the birth year, ending with a single digit.

Example: 1964 = 1 + 9 + 6 + 4 = 20 = 2 + 0 = 2

Male: Subtract that digit from 11

11 - 2 = 9

Female: Add 4 to that digit

2 + 4 = 6

Should the Life Gua (Ming Gua) add up to 5, then for a male,
convert 5 to 2; for a female, convert 5 to 8.

5 is considered to be the Evil Emperor and is to be avoided.

Since the Chinese year begins on February 4, if you were born on January 31 of 1964, you would consider yourself to have been born in 1963.

The elements are as follows:

1 Water 2 Earth 3 Wood 4 Wood

5 Earth (but not used for Ming Gua)

6 Metal 7 Metal 8 Earth (benevolent) 9 Fire

These numbers are the stars in the Flying Stars; each has its own character. Currently, we are in Period 8 which is a benevolent Earth element. Stability, family values, prosperity to those who really know what they are doing, etc., in this next twenty years.

These numbers can be used to differentiate between East and West people, but the Flying Stars are more accurate.