How to Calculate Board Feet for Hardwood Lumber
Unlike dimensional softwood lumber (which is sold by linear foot), rough-sawn hardwood lumber (such as oak, walnut, maple, and cherry) is priced and sold by the board foot. One board foot represents a volume of wood equivalent to 1 inch thick by 12 inches wide by 1 foot long (144 cubic inches).
Board Feet = [Thickness (in) × Width (in) × Length (ft)] ÷ 12