The Hamilton-Norwood classification is the most commonly used classification for grading the male pattern baldness. The Norwood scale has seven stages.
The recession of the hairline
The slight recession of the hairline around the temple
Deeply recessed at both temples, resembling an M, U, or V shape
Severe hairline recession is more than in stage 3. There is no hair on the vertex.
The two areas of hair loss are larger than stage 4.
The Temple building area is joined with the vertex baling area.
Most severe stage of hair loss. The remaining hair is usually not dense and may be fine.
Using a graft calculator is an easy way to get an idea of how many grafts you may require. But it is to be taken to mind that using a graft calculator alone is not the perfect way. From the hair transplant graft calculator, an idea of how many grafts you need can be transplanted is obtained. Always keep in mind to consult your doctor for the possible outcomes.