Board foot calculator
Price rough hardwood the way a lumber yard does: thickness in quarters, width, length, piece count. Tally, cost and weight update as you type. Cutting sheet goods instead? Use the cut list optimizer.
0.00 bf
total tally across all pieces
| Board feet per piece | 0.00 bf |
| Total cost | €0.00 |
| Estimated weight (dry, 12% MC) | 0 lb |
Weight uses the species' dry density at 12% moisture content; green, freshly sawn stock runs heavier.
Linear feet to board feet, board feet to square feet
Both conversions reuse the dimensions above: linear footage of the current board size, and the face area the tally covers at the current thickness.
| Linear feet → board feet | 0.00 bf |
| Tally → square feet covered | 0.0 ft² |
How the board-foot math works
Board feet = thickness (in) × width (in) × length (ft) ÷ 12 — one board foot is 144 in³, a 1 × 12 × 12 in slab. Hardwood is tallied on the rough thickness in quarter-inch steps: 4/4 is 1 in, 8/4 is 2 in, and surfacing it down afterward does not change what you paid for. Cost is tally × price per board foot. Weight multiplies the tally by the species' dry density at 12% moisture content (USDA Wood Handbook values); the green-density hint under the results shows what the same boards would weigh freshly sawn.
A lumber-yard tally, worked once
Hardwood yards do not price by the piece. The dealer walks the stack with a tally sheet, reads each board's width and length, and multiplies: thickness times width in inches, times length in feet, divided by twelve. Say you need stock for a workbench top: six boards of 8/4 hard maple, 6 inches wide and 8 feet long. Each board is 2 × 6 × 8 ÷ 12 = 8 board feet, the tally comes to 48 bf, and at 7.50 per bf the lot runs 360 before tax. The same 48 bf at 12% moisture content weighs about 176 lb — hard maple at 44 lb per cubic foot — so bring the truck, not the hatchback.
Two habits save money at the yard. First, buy rough and mill it yourself: the tally is billed on rough quarters, so 8/4 surfaced to 1-3/4 in still costs the 2-inch price. Second, check real coverage before overbuying — the conversion strip above turns the tally into square feet at your thickness. If the project mixes plywood with solid stock, the cut list optimizer lays the parts out on sheets. Shelving in the same build? Run the shelf sag calculator before committing to a span, and the epoxy calculator if a river pour is involved. The rest of the woodworking tools are linked below.
Frequently asked questions
What is a board foot?
A board foot is a volume unit for lumber: 144 cubic inches — a board 1 inch thick, 12 inches wide and 12 inches long. Hardwood in North America is priced per board foot, so the yard tallies every board you buy with the same formula instead of pricing per piece.
What is the board foot formula?
Thickness (inches) × width (inches) × length (feet) ÷ 12. A 2 in × 6 in × 8 ft board is 2 × 6 × 8 ÷ 12 = 8 board feet. The calculator above applies it per piece and multiplies by your piece count for the tally.
What does 4/4 mean in lumber?
Hardwood thickness is sold in quarters of an inch, rough-sawn: 4/4 is 1 in, 5/4 is 1-1/4 in, 6/4 is 1-1/2 in, 8/4 is 2 in. Surfacing removes roughly 1/4 in (4/4 S2S finishes near 3/4 in), but the tally is always billed on the rough quarter thickness.
What is the difference between board feet and square feet?
Square feet measure face area; board feet measure volume. Divide board feet by the thickness in inches to get coverage: 12 bf of 4/4 (1 in) stock covers 12 ft², while 12 bf of 8/4 (2 in) covers only 6 ft². The conversions strip above does this at your current thickness.
What is the difference between board feet and linear feet?
A linear foot is just length — a 10 ft 2×4 and a 10 ft 1×12 are both 10 linear feet. Board feet add thickness and width: bf = thickness (in) × width (in) × linear feet ÷ 12, so 10 linear feet of 4/4 × 6 in stock is 5 bf. Dimensional softwood is usually priced per linear foot, hardwood per board foot.