There are two ways of methods to measure the width of your hair.
The Light Method
1.Gather sheds hair strands from your comb or brush to examine.
2. Hold the hair up to the light.
3. If the hair is very wide and easily visible, then you have coarse hair. If it's so thin that you can hardly see it, you have fine hair. If your hair appears neither thin nor coarse, you have medium width hair.
The Thread Method
1.Gather sheds hair strands from your comb or brush to examine. Use tape to stick the strands to a piece of white paper on either end ensuring that they are stretched out and pulled tight.
2. Next, take a strand of thread and pull it apart to separate it into two strands. Do the same as above and stick one of those strands to the paper on either end, ensure it is stretched out and pulled tight.
3.Compare your hair strands to the strand of thread. If your hair is thinner than the strand of thread then your hair is fine. If it is around the same thickness then your hair is of medium width and if it is thicker than the strand then your hair is referred to as coarse.