ToolnozaBoard foot formula
For dimensions in inches and length in feet: board feet = thickness (in) × width (in) × length (ft) ÷ 12. Multiply by the number of boards for a total. One board foot is a volume of 144 cubic inches, equivalent to a 1 × 12 × 12 inch piece.
Example for a lumber order
Ten boards each measuring 2 inches thick, 6 inches wide and 8 feet long contain 2 × 6 × 8 × 10 ÷ 12 = 80 board feet. The Toolnoza calculator takes thickness, width, length and board count as inputs.
Nominal versus actual dimensions
Lumber is often sold by a nominal size that differs from its finished dimensions. A nominal 2 × 6 board may measure less after drying and surfacing. For estimating physical volume, decide whether your project or supplier uses nominal or actual dimensions and be consistent.
Estimating material and price
Board feet measure volume, not the number of boards or the covered floor area. Add a separate waste allowance for cuts, defects and project layout. To estimate cost, multiply total board feet by the quoted price per board foot and confirm grading, species, moisture and delivery charges with the supplier.
Frequently asked questions
How many cubic inches are in a board foot? 144. Can I mix inches and feet? Use the stated formula: thickness and width in inches, length in feet. Does board footage tell me exact finished yield? No; actual dimensions, cuts and defects affect usable material.