How this calculator works
A board foot is a unit of lumber volume equal to 12 × 12 × 1 inch. Multiply thickness (in) × width (in) × length (ft), divide by 12, then multiply by the number of boards. Use the lumberyard's actual surfaced dimensions, not a nominal label like 1×6.
(1 × 6 × 8) ÷ 12 = 4 board feet each × 10 = 40 board feet. At $4 per board foot, the lumber estimate is $160 before tax and delivery.
Plan the lumber order from a cut list
Hardwood (oak, maple, walnut) is commonly priced by the board foot; softwood framing lumber is often sold by the piece or linear foot. For a mixed cut list, calculate each stock size as its own line and add the board-foot totals before applying the waste allowance. For example, four 1 × 6 × 8 ft boards equal 16 board feet; with 10% waste, plan to buy at least 17.6 board feet, then choose available board lengths that cover the cut list. Add 10–15% when your cut list has defects, matching grain, or short offcuts, and buy longer boards only after checking the usable cuts. For decking measured by coverage rather than volume, use the deck board calculator.
Frequently asked questions
What is a board foot of lumber?
One board foot equals 144 cubic inches — the volume of a piece 1 inch thick, 12 inches wide, and 1 foot long.
How do I calculate board feet?
Multiply thickness (inches) × width (inches) × length (feet), then divide by 12.
Should I use nominal or actual lumber dimensions?
Use the lumberyard's actual surfaced thickness and width for board-foot pricing. Nominal labels such as 1×6 can describe a different finished size.
How much extra hardwood should I order?
A 10–15% allowance is a practical starting point for defects, grain matching, and offcuts. Complex parts or short stock can require more.