Someone told me that it would take almost 12,000 grafts on a completely bald level 5 on the Norwood scale of hair loss. But I thought that the Norwood scale number times a thousand was based on how many grafts were required to give adequate coverage on top of the head with hair transplant surgery? So shouldn't a Norwood 5 require 5000 grafts and a Norwood 6 require 6000 grafts? I actually have found this not to be true in most cases though.
It sounds like you've taken some information you've read out of context.
The Hamilton-Norwood scale is a model to help classify hair loss patterns - the higher the number, the greater the degree of hair loss. The Norwood scale was developed independently of hair transplant surgery.
However, as an attempt to reconcile the two, some have concluded that multiplying your Norwood level by 1000 to 1500 can give patients and idea as to an approximate (keyword) number of grafts needed to achieve realistic (keyword) goals.
Remember though that hair restoration surgeons usually don't create uniform density, giving a greater illusion of hair density in the front than the back with a finite number of grafts.
Theoretically, to achieve any real uniform hair density on a completely bald Norwood level 5, a lot more will be needed, but most hair transplant patients don't have the number of follicular units needed to acquire such density. Thus, the number of grafts available must be used strategically to accomplish a patient's realistic goals.
Bill Associate Publisher/Editor