Multiply thickness (in) × width (in) × length (), then divide by 12.
(or board footage) is the standard unit used to measure the volume of lumber, primarily for hardwood and rough-sawn stock. Unlike linear feet (length) or square feet (area), it accounts for the board's thickness , width , and length to determine its total volume. The Fundamental Unit
One board foot is defined as a piece of lumber that contains of wood. A standard visual for this is a board that is: 1 inch thick 12 inches wide 1 foot (12 inches) long How to Calculate Board Feet