Methodology
Formula & assumptions
Perimeter per bed
2 × (length + width)
Models four rectangular bed walls.
Wall courses
target wall height ÷ installed board face height, rounded up
Uses the actual exposed/stacked face height.
Linear stock target
perimeter × courses × bed count × (1 + allowance)
Keeps cut/defect reserve explicit.
Whole boards
linear stock target ÷ stock length, rounded up
Rounds only to sold stock pieces.