Hair growth is a gradual process in which hair follicles produce keratin, a protein that makes up the hair strand. The hair strand then emerges from the follicle and grows outward. On average, hair grows about half an inch per month or about 6 inches per year. However, the rate of hair growth can vary depending on factors such as genetics, age, hormone levels, and overall health. Additionally, hair growth can be affected by external factors such as diet, stress, and certain hairstyles or treatments.