Follicular unit transplantation (FUT) is a method of hair restoration surgery that relocates hair in follicular units, its naturally occurring groupings. The small size of the units allows for great ease in their placement, the creation of hair patterns that closely mimic nature and the transplantation of a large enough number of grafts so that a full restoration can often be achieved in just one or two sessions. FUT requires large numbers of grafts, so it is important to accurately assess patients’ donor reserves in the initial planning. Densitometry enables the physician to estimate the total amount of movable hair, the size of the individual follicular units, and the degree of miniaturization in both the donor and recipient areas; scalp laxity assessment is also crucial to the surgical planning.