Introduction to Lumber Measurement: Board Feet (BF)
In woodworking and lumber trading, hardwood is sold using a unique unit of volume called the Board Foot (BF). A board foot is defined as a volume equivalent to a board that is 12 inches wide, 12 inches long, and 1 inch thick (144 cubic inches).
Unlike softwoods (which are sold by standard dimensional lengths, e.g., 2x4 studs), hardwoods are often sold in rough-sawn random widths and lengths. That is why measuring board feet is necessary to calculate pricing.
The formula for calculating board feet is: BF = (Thickness (in) × Width (in) × Length (ft))/12 × Quantity. If the board length is measured in inches, the formula becomes: BF = (Thickness (in) × Width (in) × Length (in))/144 × Quantity. Hardwood thickness is often designated in quarters: 4/4 lumber is 1 inch thick, 8/4 is 2 inches thick, and 12/4 is 3 inches thick.