Sheets for the walls this lumber frames.
Open the calculator →
Board Foot Calculator
LumberQuick answer: a board foot is a volume — 144 cubic inches of wood — not a length. This calculator turns your board dimensions into board feet and a lumber bill. Ten 1×6 boards, 8 ft long, are 40 board feet — about $240 at $6 per board foot.
–
Board feet per board
–
Total board feet to buy
–
Exact board feet (no waste)
–
Total linear feet
–
Estimated lumber cost
Board feet here use the dimensions you enter. Lumber yards bill rough lumber on nominal dimensions before surfacing — a surfaced '1 inch' board is really 3/4 inch thick, but it is still sold as the nominal size. Enter nominal sizes to match the yard's tally.
How it works — the formula
Board feet per board = (Thickness in × Width in × Length ft) ÷ 12 Total to buy = Board feet per board × Quantity × (1 + waste %)| Common board | Board feet per foot of length | Example: 8 ft board |
|---|---|---|
| 1 × 4 | 0.33 BF/ft | 2.67 BF |
| 1 × 6 | 0.50 BF/ft | 4.00 BF |
| 1 × 8 | 0.67 BF/ft | 5.33 BF |
| 2 × 4 | 0.67 BF/ft | 5.33 BF |
| 2 × 6 | 1.00 BF/ft | 8.00 BF |
| 2 × 12 | 2.00 BF/ft | 16.00 BF |
One board foot = 144 cubic inches (a 12 × 12 × 1 inch piece). Hardwood yards price by the board foot because widths and lengths vary; the same formula also works for logs' rough estimates, though a log scale (Doyle, Scribner) gives a lower, yield-based figure.
Worked examples
| Boards | BF per board | Total BF | Est. cost |
|---|---|---|---|
| 10 × (1 × 6 × 8 ft), no waste, $6/BF | 4.00 | 40.0 | $240 |
| 5 × (2 × 4 × 10 ft), no waste, $5/BF | 6.67 | 33.3 | $167 |
| 3 × (2 × 6 × 12 ft), 10% waste, $7/BF | 12.00 | 39.6 | $277 |
Check the first row: (1 × 6 × 8) ÷ 12 = 4 board feet per board; times 10 boards = 40 BF.
Frequently asked questions
How do I calculate board feet?
(Thickness in × Width in × Length ft) ÷ 12. A 1×6, 8 ft long: (1 × 6 × 8) ÷ 12 = 4 BF.
How many board feet are in a 2x4x8?
(2 × 4 × 8) ÷ 12 = 5.33 BF nominal. Construction 2x4s are usually priced per piece, not per board foot.
Why does the yard's count differ from mine?
Yards bill nominal (pre-surfacing) dimensions and often round up per board. A tape on a surfaced board understates the tally by design.
How much waste should I add for hardwood?
≈5% for clear pick-through stock; 10–15% for furniture parts from common grades; more for short parts from long boards.
What is a good price per board foot?
Species decides: red oak a few dollars, walnut several times that. Enter your yard's quote for a true comparison.
Related tools
Heat and cool the workshop the lumber is for.
Open the calculator →
Yards for the slab the project sits on.
Open the calculator →
Base material in yards and tons.
Open the calculator →
See the full list on the Home & DIY Calculators page.
Estimates only. Board-foot tallies follow the yard's nominal-dimension convention; confirm species, grade and tally method with your supplier before a large order.