Hair density is the amount of hair strands on the head. Generally, it
is measured by counting the number of hair strands found in one square
inch (2.5cm) of scalp. When a stylist tells you that you have thick hair, it is high density he/she is describing.
Generally, the classifications of hair density are thin, medium, and thick, and are unrelated to the texture of
the hair. The average head has approximately 2,200 strands of hair per
square inch, and a total of approximately 100,000 hairs.
The main consideration of hair density is in styling. Thick hair is well
suited to layered styles, while thin hair is often better suited to more
blunt styles. People with thin hair often prefer styles with added curl to give an illusion of more hair.
While there is not a true ethnic or racial determiner of hair density,
it has been found that blondes tend to have the greatest hair density, while redheads have the lowest.