What is a board foot?
A board foot is a volume of wood 12 inches long, 12 inches wide and 1 inch thick, which is 144 cubic inches. The formula is thickness (in) × width (in) × length (ft) ÷ 12. A board 1 inch thick, 6 inches wide and 8 feet long is 1 × 6 × 8 ÷ 12 = 4 board feet.
Quarters, nominal and actual sizes
Rough hardwood thickness is given in quarters of an inch: 4/4 is 1 inch, 6/4 is 1.5 inches and 8/4 is 2 inches. Softwood dimensional lumber is named by nominal size, so a 2 × 4 is really about 1.5 × 3.5 inches. Board feet for softwood are usually calculated from the nominal size; enter whichever size your yard prices by.
Frequently asked questions
How many board feet are in a 2 × 4 × 8?
Using nominal size: 2 × 4 × 8 ÷ 12 = 5.33 board feet.
How do I price lumber by the board foot?
Multiply the board feet by the price per board foot. Enter the price above and the calculator does it for you.
Why is hardwood sold by the board foot?
Rough hardwood comes in random widths and lengths, so pricing by volume is fairer than pricing per board.