Everyone has different areas of hair loss, so the area needed for hair transplantation is often the key to determine the number of hair follicles. The larger the hair loss area, the more hair follicles naturally need to be transplanted. Hair follicle transplantation with more than 2000 units is called tertiary alopecia, but if the number of hair follicle transplantation exceeds 3500 units, the price will be higher. Therefore, the amount of hair transplantation is closely related to the area of hair loss and the number of hair follicles.