To find out the overall thickness of your hair:
Look into the mirror and take a section of hair at the side of your head. Now look at the scalp around it.
If you cannot see your scalp, you have thick hair.
If what you see is somewhere in the middle, you have normal hair.
How to find the right brush for your type of hair:
Finding the right brush for your hair is easy - all you need is to know if you have fine, normal or thick hair. How fine or thick your hair is, relates to the thickness of a single hair as well as the total amount of hair.
To find out the thickness of a single hair:
Take a single hair between your fingers.