Board Foot Calculator — Lumber Volume & Cost
Who this is for: For woodworkers and contractors buying hardwood by the board foot — what a glue-up, a tabletop, or a staircase job actually costs before the yard's rounding rules land.
Lumber volume in board feet: thickness × width × length × pieces, with price-per-bf to get the cost — hardwood pricing without the guesswork.
Quick answer: Board feet = thickness (in) × width (in) × length (ft) ÷ 12. A 1-inch × 8-inch × 10-foot board is 6.67 bf; a 2×6×10 is 10 bf. Yards round each board up to the next foot — budget +5-10%.
4/4 = 1 in · 8/4 = 2 in
| Formula | T in × W in × L ft ÷ 12 = board feet |
|---|---|
| One board foot | 144 in³ = 1/12 ft³ |
| 4/4 stock | 1 inch rough thickness |
| Yard rounding | Per-board, up to next foot |
How do you calculate board feet?
One board foot is 144 cubic inches of rough lumber: thickness (inches) × width (inches) × length (feet) ÷ 12. A 4/4 (1-inch) board 8 inches wide and 10 feet long is 1 × 8 × 10 ÷ 12 = 6.67 board feet. Multiply by piece count for the order, then by the yard's price per board foot. The conventions that trip people up: hardwood thickness is quoted in quarters (4/4 = 1 inch rough, 8/4 = 2 inches); width is the rough width before milling; and most yards round each board up to the nearest foot and price from the sticker's thinnest point — so the calculator's number is your negotiating baseline, and the invoice will usually run a little higher.
Common uses
- Pricing hardwood for tabletops, shelves, and glue-ups
- Converting a cut list into yard-side board-foot totals
- Comparing 4/4 vs 8/4 stock costs for a project
- Checking an invoice against your own takeoff