Density (grafts/cm²)
The number of grafts implanted per square centimetre of recipient scalp. Natural-looking results balance density against blood supply limits and total donor reserves.
Density in transplant planning means implanted grafts per square centimetre of recipient scalp — the number that connects a surface area to a graft count, and the setting that trades coverage today against blood supply, graft survival and the donor budget. It is decided zone by zone, not as one figure for the whole head, and in consultation notes it should appear per zone, next to the area measurements it multiplies.
The first honest fact is that no transplant restores native density. A balding scalp once carried far more follicular units per square centimetre than any donor can fund across the areas that need them; results look full because vision is forgiving — hair calibre, curl, colour contrast against skin, and hair layering over hair all multiply the effect of each graft. That is why coverage well below native numbers reads as a full head, and why identical densities look different on different patients. Hairs per graft fold in as well: the same density delivers very different hair numbers depending on unit composition.
Pushing density up is not free. Each additional channel per square centimetre crowds the local blood supply every graft in the zone depends on; beyond a point — which varies with scalp character and technique — packing risks trading planted numbers for grown ones. High-density work exists and can succeed, but it is a deliberate technique with its own demands, not a default promise. The donor side is the harder constraint: density spent on one zone is area left uncovered somewhere else, now or in ten years.
Planning therefore assigns density strategically: soft, lower-density single-hair work at the hairline transition, the strongest packing in the frontal core that frames the face, and disciplined economy in the crown, which swallows grafts and keeps receding. When a plan quotes one density everywhere, or a density the donor arithmetic cannot fund, the plan is a brochure. The revealing consultation question is zonal: what density where — and what is deliberately being saved for later?
