Graft calculation
Estimating the number of grafts needed from the recipient surface area and target density, balanced against donor reserves and future loss progression. The basis of honest surgical quotes.
Graft calculation is the arithmetic that turns a hair loss pattern into a surgical plan: measure the recipient area in square centimetres, assign a target density to each zone, multiply, and then test the total against what the donor can afford — now and across the patient’s lifetime. Every honest quote in this field is built on that sequence; most dishonest ones skip straight to a number.
The recipient side is zonal, not global: hairline transition, frontal core, mid-scalp and crown carry different densities, with single-hair grafts budgeted separately for the transition. The donor side is a capacity estimate — total available units in the safe zone, minus the visual density that must remain, minus a reserve for future sessions. When recipient demand exceeds donor supply, and in progressed patterns it routinely does, calculation becomes triage: the frontal frame that shapes the face is usually funded first, and the crown — a large area that is forgiving to defer and keeps expanding — is where restraint pays.
Progression is the variable that turns arithmetic into judgement. The calculation is not for today’s pattern but for the pattern a decade out: a plan that spends the whole donor on a stage the disease will outgrow strands the patient with an island of transplanted hair and nothing left to fix it. Age, family history, trichoscopic miniaturisation mapping and the stabilising effect of medical treatment all feed the projection.
The calculation is also a commercial audit point. Quotes should show their working — zones, areas, densities, totals — because a number without working can be inflated (per-graft pricing rewards it) or padded with hairs masquerading as grafts. A written calculation in the consultation record protects both sides: the patient can compare like with like, and the clinic can explain, years later, exactly why it planned what it planned. When two quotes differ by thousands of grafts for the same head, at least one of them was not calculated.
