Each person who asks for hair transplantation has a varied capacity for the donor area (the place where the hair follicles will be extracted). At the same time, the amount of graft required for the specific planting area varies. If the total number of grafts required is high, parameters such as the number of grafts per square centimeter in the donor area, the thickness of the hair strand, and the average number of hair strands per graft are calculated, and the root is cut to a depth that does not harm the donor area are calculated.