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Lumber & Framing

Board Feet Calculator

Calculate board feet for lumber purchases and project planning.

Enter dimensions
Total board feet board feet
board feet
Board feet is the standard unit of measurement for buying and selling hardwood lumber in the United States. Unlike dimensional softwood lumber that you buy by the piece at a set price per length, hardwood is sold by the board foot because each piece varies in width and length. One board foot equals a piece of wood 1 inch thick, 12 inches wide, and 12 inches long, or 144 cubic inches of lumber. This calculator works for any combination of thickness, width, and length. Enter the nominal dimensions of each board and how many pieces you need. The result is the total board footage, which you can multiply by the per-board-foot price to estimate your lumber cost. When shopping for hardwood, thickness is described in quarters of an inch. A 4/4 board is 1 inch thick rough, a 5/4 board is 1.25 inches, a 6/4 board is 1.5 inches, and an 8/4 board is 2 inches thick. After surfacing and planing, the finished thickness will be slightly less. A surfaced 4/4 board typically finishes at 13/16 inch. However, you are still charged for the rough thickness when buying by the board foot. Hardwood pricing varies enormously by species. Poplar might run 3 to 5 dollars per board foot while walnut can be 10 to 15 dollars and exotic species like ebony can exceed 50 dollars per board foot. Always factor in a waste allowance of 15 to 25 percent when planning a project, since you will lose material to defects, cutting waste, and jointing edges straight. For softwood dimensional lumber like 2x4s and 2x6s, board feet is less commonly used at retail but still useful for estimating large framing orders. A standard 2x4x8 contains 5.33 board feet. A 2x6x12 contains 12 board feet.