The number of hair in the donor area measured per square centimeter. The higher number of hairs per square centimeter, i.e., the greater the donor density, the more “paint”, i.e., hairs, that can be used to paint the “canvas”i.e., the bald scalp. An individual with high donor density can have a much higher chance of filling a wide area of baldness than someone with medium or low hair density. Donor density ranges in general between 60 to 120 follicular units per square centimeter.