- On average, each person's head carries about 100,000 hair follicles. Some people have as many as 150,000.
- On a baby's head, there are about 1,100 follicles per square centimetre.
- By the age of 25, this number has fallen to about 600, but the number depends on the physical type of the individual.
- Between the ages of 30 and 50, the number drops further, to 250-300. There is only a slight further fall with age.
- Each follicle grows about 20 new hairs in a lifetime. Each new hair grows for several years, and can reach over a metre in length.
- Each hair falls out eventually, and is replaced by a new one.