★ CONSTRUCTION · LUMBER · WOODWORKING
80.00 board feet for $360.00. Ten 2x6 boards at 8 ft long are 8.00 board feet each — 80.00 in all, 6.67 cubic feet, $36.00 a board. A $500 budget buys 13 boards. Enter your lumber size and price to work out the board feet and the cost.
A board foot is 144 cubic inches: the thickness in inches times the width in inches times the length in feet, divided by 12. This calculator works out the board feet in one board and in the whole order, the cost, the cubic feet, and how many boards a budget buys — so the number you get is the number on the invoice.
A board foot is 144 cubic inches: the volume of a board 1 in thick, 12 in wide and 1 ft long. The board feet in one board are the thickness in inches times the width in inches times the length in feet, divided by 12. The total board feet are the per-board figure times the number of boards, and the cost is the total times the price per board foot. One board foot is 0.08 cu ft (1/12 cu ft), so the cubic feet are the total board feet divided by 12, and the cubic inches are the total times 144.
At the defaults — thickness 2 in, width 6 in, length 8 ft, 10 boards, price $4.50 a board foot — one board is 2 × 6 × 8 ÷ 12 = 8.00 board feet, ten boards are 80.00 board feet, and the cost is 80.00 × $4.50 = $360.00. The volume is 80.00 × 144 = 11,520 cu in, which is 80.00 ÷ 12 = 6.67 cu ft. Each board costs $36.00, and each linear foot costs $4.50.
| Case | Per board | Total | Cost |
|---|---|---|---|
| Default (2x6x8, 10 boards) | 8.00 bf | 80.00 bf | $360.00 |
| 2x4x8 | 5.33 bf | 53.33 bf | $240.00 |
| 1x6x8 | 4.00 bf | 40.00 bf | $180.00 |
| 4x4x8 | 10.67 bf | 106.67 bf | $480.00 |
| 2x8x10 | 13.33 bf | 133.33 bf | $600.00 |
| 2x10x12 | 20.00 bf | 200.00 bf | $900.00 |
| 1x12x8 | 8.00 bf | 80.00 bf | $360.00 |
| Price $3.00/bf | 8.00 bf | 80.00 bf | $240.00 |
| Price $6.00/bf | 8.00 bf | 80.00 bf | $480.00 |
| 20 boards | 8.00 bf | 160.00 bf | $720.00 |
| 5 boards | 8.00 bf | 40.00 bf | $180.00 |
| Length 10 ft | 10.00 bf | 100.00 bf | $450.00 |
| Length 12 ft | 12.00 bf | 120.00 bf | $540.00 |
Setup: thickness 2 in, width 6 in, length 8 ft, 10 boards, price $4.50 a board foot.
Line 1 — the board feet in one board. 2 × 6 × 8 ÷ 12 = 96 ÷ 12 = 8.00 board feet.
Line 2 — the total board feet. 8.00 × 10 = 80.00 board feet.
Line 3 — the cost. 80.00 × $4.50 = $360.00.
Line 4 — the volume. 80.00 × 144 = 11,520 cu in, which is 80.00 ÷ 12 = 6.67 cu ft.
Line 5 — the cost per board and per foot. Each board costs 8.00 × $4.50 = $36.00, and each linear foot costs 8.00 ÷ 8 × $4.50 = $4.50.
Reverse: a $500 budget buys $500 ÷ $4.50 = 111.11 board feet, which is 111.11 ÷ 8.00 = 13.89 boards, so 13 boards cost $468.00 and 14 boards cost $504.00 — $4 over the budget. 100 board feet need 100 ÷ 8.00 = 12.50, rounded up to 13 boards; 50 board feet need 50 ÷ 8.00 = 6.25, rounded up to 7 boards, which cost $252.00.
2x4x8: one board is 2 × 4 × 8 ÷ 12 = 5.33 board feet, ten boards are 53.33 board feet, and the cost is $240.00. The narrower board carries a third less than the 2x6.
1x6x8: one board is 1 × 6 × 8 ÷ 12 = 4.00 board feet, ten boards are 40.00 board feet, and the cost is $180.00. Half the thickness is half the board feet.
4x4x8: one board is 4 × 4 × 8 ÷ 12 = 10.67 board feet, ten boards are 106.67 board feet, and the cost is $480.00. The post carries a third more than the 2x6.
2x8x10: one board is 2 × 8 × 10 ÷ 12 = 13.33 board feet, ten boards are 133.33 board feet, and the cost is $600.00. A longer, wider board carries far more than a 2x6x8.
2x10x12: one board is 2 × 10 × 12 ÷ 12 = 20.00 board feet, ten boards are 200.00 board feet, and the cost is $900.00. The biggest board here is two and a half times the default.
1x12x8: one board is 1 × 12 × 8 ÷ 12 = 8.00 board feet, ten boards are 80.00 board feet, and the cost is $360.00 — the same as the 2x6x8, because the volume is the same.
Price $3.00/bf: the total is still 80.00 board feet, and the cost is 80.00 × $3.00 = $240.00. The price changes the cost, never the board feet.
Price $6.00/bf: the cost is 80.00 × $6.00 = $480.00. A $1.50 dearer price adds $120.00 on this order.
20 boards: the total is 8.00 × 20 = 160.00 board feet, and the cost is $720.00. Twice the boards is twice the board feet and twice the cost.
5 boards: the total is 8.00 × 5 = 40.00 board feet, and the cost is $180.00.
Length 10 ft: one board is 2 × 6 × 10 ÷ 12 = 10.00 board feet, ten boards are 100.00 board feet, and the cost is $450.00.
Length 12 ft: one board is 2 × 6 × 12 ÷ 12 = 12.00 board feet, ten boards are 120.00 board feet, and the cost is $540.00.
Reverse — the budget and the target: a $500 budget buys 111.11 board feet, which is 13.89 boards, so 13 boards cost $468.00 and 14 boards cost $504.00. 100 board feet need 13 boards (12.50, rounded up); 50 board feet need 7 boards (6.25, rounded up), which cost $252.00.
Edges: one board foot is 144 cu in, which is 0.08 cu ft (1/12 cu ft); 80.00 board feet are 11,520 cu in, which is 6.67 cu ft.
The model assumes the nominal size you enter — a 2x6 is taken as 2 in by 6 in, not its actual 1.5 by 5.5 in — and it assumes a single price per board foot for the whole order, with no waste, no tax and no delivery. It assumes every board is the same size, and it leaves out the cut list, the kerf and the offcuts, which are real but not priced here. Rounding convention: board feet are shown to two decimals, money is rounded to cents, and all figures are computed from unrounded values, rounded only for display.
| Output | Formula | What it means |
|---|---|---|
| Board feet per board | thickness (in) × width (in) × length (ft) ÷ 12 | 8.00 bf. |
| Total board feet | per-board × boards | 80.00 bf. |
| Total cost | total × price per board foot | $360.00. |
| Cubic inches | total × 144 | 11,520 cu in. |
| Cubic feet | total ÷ 12 | 6.67 cu ft. |
| Cost per board | per-board × price | $36.00. |
| Cost per linear foot | per-board ÷ length × price | $4.50/ft. |
| $500 budget buys | $500 ÷ price | 111.11 bf (13.89 boards). |
| 13 boards cost | 13 × per-board × price | $468.00. |
| 14 boards cost | 14 × per-board × price | $504.00. |
| 100 board feet need | ceil(100 ÷ per-board) | 13 boards. |
| 50 board feet need | ceil(50 ÷ per-board) | 7 boards. |
| 7 boards cost | 7 × per-board × price | $252.00. |
| 2x4x8 | same model, 2x4x8 | 5.33 bf/board, 53.33 bf total, $240.00. |
| 1x6x8 | same model, 1x6x8 | 4.00 bf/board, 40.00 bf total, $180.00. |
| 4x4x8 | same model, 4x4x8 | 10.67 bf/board, 106.67 bf total, $480.00. |
| 2x8x10 | same model, 2x8x10 | 13.33 bf/board, 133.33 bf total, $600.00. |
| 2x10x12 | same model, 2x10x12 | 20.00 bf/board, 200.00 bf total, $900.00. |
| 1x12x8 | same model, 1x12x8 | 8.00 bf/board, 80.00 bf total, $360.00. |
| Price $3.00/bf | same model, $3.00/bf | 8.00 bf/board, 80.00 bf total, $240.00. |
| Price $6.00/bf | same model, $6.00/bf | 8.00 bf/board, 80.00 bf total, $480.00. |
| 20 boards | same model, 20 boards | 8.00 bf/board, 160.00 bf total, $720.00. |
| 5 boards | same model, 5 boards | 8.00 bf/board, 40.00 bf total, $180.00. |
| Length 10 ft | same model, 10 ft long | 10.00 bf/board, 100.00 bf total, $450.00. |
| Length 12 ft | same model, 12 ft long | 12.00 bf/board, 120.00 bf total, $540.00. |
The math is exact for the numbers you enter: the board feet in one board are the thickness times the width times the length divided by 12, the total is the per-board figure times the number of boards, and the cost is the total times the price. What the model cannot do is measure your lumber for you: check the thickness, width and length on the board, because a 2x10x12 and a 2x6x8 differ by 12.00 board feet a board. It uses nominal sizes, not actual sizes, and it leaves out waste, tax, delivery, the cut list, the kerf and the offcuts. For the concrete that goes under the lumber, see concrete driveway cost calculator; for the paint that goes on it, see paint roller size chart.
Bright Side Kit. "Board Foot Calculator: Lumber Board Feet & Cost 2026." https://brightoolbox.com/board-foot-calculator/ Accessed October 25, 2026.One board foot is 144 cubic inches. It is the volume of a board 1 in thick, 12 in wide and 1 ft long, and it is the unit lumber is priced by. One board foot is 0.08 cu ft (1/12 cu ft), so 80 board feet are 6.67 cu ft.
Thickness in inches times width in inches times length in feet, divided by 12. At the defaults that is 2 × 6 × 8 ÷ 12 = 8.00 board feet a board, and 10 boards are 80.00 board feet, which cost $360.00 at $4.50 a board foot.
5.33 board feet. A 2 by 4 that is 8 ft long is 2 × 4 × 8 ÷ 12 = 5.33 board feet, and 10 of them are 53.33 board feet, which cost $240.00 at $4.50 a board foot. A 2x6x8 is 8.00 board feet a board, so the wider board carries half again as much.
$450.00 at $4.50 a board foot. At the defaults 100 board feet need 13 boards (100 ÷ 8 = 12.50, rounded up to whole boards), and 13 boards are 104 board feet for $468.00. At $3.00 a board foot 100 board feet cost $300.00, and at $6.00 they cost $600.00.
7 boards. At 8.00 board feet a board, 50 board feet need 50 ÷ 8 = 6.25 boards, rounded up to 7 whole boards, which are 56 board feet for $252.00. Buying 6 boards gives only 48 board feet, which is short.
111.11 board feet, or 13 boards. At $4.50 a board foot, $500 buys $500 ÷ $4.50 = 111.11 board feet, which is 13.89 boards of the default size, so 13 boards cost $468.00 and 14 boards cost $504.00 — $4 over the budget.
$4.50 a linear foot at the defaults. A 2x6 carries 1.00 board foot a linear foot (2 × 6 ÷ 12), so at $4.50 a board foot it costs $4.50 a foot. A 2x4 carries 0.67 board feet a foot, so it costs $3.00 a linear foot at the same price.