The fastest growing tissue in your body is the hair. Every day on the scalp of an average adult, 35 meters (over 100ft)of hair fibers are produced. Quite difficult to imagine, isn't it. But consider that the average scalp consist of about 100,000 hairs (120,000 if you are a blond, 100,000 if you are a brunette and just 80,000 if you are redheaded). The average growing speed of hair is 1.25 cm (0.5 in) per month or 15 cm (6 in) per year.