Graft maths: how we calculate your number, with three cases

The arithmetic behind every estimate

Every honest graft number comes from two measurements multiplied together: the recipient area in square centimetres, and the density in grafts per square centimetre that the area needs. We mark the area on your photographs, measure it against a fixed reference, and plan 40 to 50 grafts per square centimetre — enough to read as full at conversational distance without exhausting the donor. Then we check that answer against what your donor can actually give.

Case one: Norwood 3, thirty-two years old

Frontal recession and temples measured 38 square centimetres. At 45 grafts per square centimetre that is roughly 1,700 grafts. Donor density measured 82 follicular units per square centimetre across a usable donor of about 120 square centimetres, so the lifetime reserve is comfortable and a single session covers the plan. He fits the €1,800 package with grafts left for the crown in fifteen years, which at thirty-two is the number that actually matters.

Case two: Norwood 5, split over two days

Front and mid-scalp came to 55 square centimetres, the crown another 40. Ninety-five square centimetres at 45 grafts each is 4,275 — more than we place safely in one day, and more than his donor could give without visible thinning at the back. The plan was 2,800 grafts to the front and mid-scalp first, with the crown reassessed at month twelve. Front first is not a sales decision; it is what frames the face.

Case three: when the arithmetic says no

A woman with a widened part measured 30 square centimetres, which reads as roughly 1,350 grafts. Her donor density was 55 follicular units per square centimetre and thinning diffusely, so harvesting would have thinned the back to improve the top. We declined surgery, treated the ferritin deficiency her bloodwork showed, and reassessed after nine months. The arithmetic is not there to sell a number — it is there to tell us when to say no.