Total the board feet of lumber for a project. Add each piece with its thickness, width, length and quantity, and the calculator totals the board feet and estimated cost.
| Piece | Thick in | Width in | Length ft | Qty | Board Ft |
|---|
A board foot is a unit of hardwood lumber volume equal to 144 cubic inches—a piece 12 inches wide, 12 inches long and 1 inch thick. To find the board feet in a piece, multiply its thickness in inches by its width in inches by its length in feet, then divide by 12. Multiply by the quantity for identical boards.
Use nominal (rough) thickness for hardwood priced by the board foot: 4/4 stock counts as 1 inch even after surfacing. Add about 10% for waste, defects and cutoffs, more for projects with lots of short or angled cuts. Board feet measure volume, unlike linear feet, which measure only length.
Use the board foot calculator when lumber is sold by volume rather than by the piece. It is most useful for hardwood, rough stock and custom millwork lists where thickness, width, length and quantity vary by row.
Start with the calculator that matches how your material is sold: area, length, volume, count, weight or electrical load. Enter one work area at a time, use the unit selector beside each measurement, then review the order quantity and cost fields before comparing supplier quotes.
Most calculators can save the current estimate in your browser, reload named estimates, print a copy, switch to dark mode or create a shareable link. Those tools are intended for planning and communication; always confirm final quantities, coverage rates, density, code requirements and pricing with the supplier or contractor responsible for the work.