Board foot calculator
Thickness in quarters (4/4, 8/4) or inches, width in inches and length in feet. Get the board feet of every board, the total to buy and what it costs.
How to calculate board feet
A board foot is a piece 12 inches long, 12 inches wide and 1 inch thick: 144 cubic inches.
Board feet = thickness (in) × width (in) × length (ft) ÷ 12
- A 4/4 board, 6 inches wide and 8 ft long: 1 × 6 × 8 ÷ 12 = 4 board feet.
- A 2×4 that is 8 ft long: 2 × 4 × 8 ÷ 12 = 5.33 board feet.
- An 8/4 board, 4 inches wide and 6 ft long: 2 × 4 × 6 ÷ 12 = 4 board feet.
Lumber yards price hardwood on the rough thickness (4/4 is a full inch before planing), and dimensional lumber on its nominal size, so use those figures, not the planed size.
Quarter sizes
| Quarters | Rough thickness |
|---|---|
| 4/4 | 1" |
| 5/4 | 1 1/4" |
| 6/4 | 1 1/2" |
| 8/4 | 2" |
| 10/4 | 2 1/2" |
| 12/4 | 3" |
| 16/4 | 4" |
Board feet chart
| Nominal size | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|
| 1×4 | 2.67 | 3.33 | 4.00 | 5.33 |
| 1×6 | 4.00 | 5.00 | 6.00 | 8.00 |
| 1×8 | 5.33 | 6.67 | 8.00 | 10.67 |
| 1×12 | 8.00 | 10.00 | 12.00 | 16.00 |
| 2×4 | 5.33 | 6.67 | 8.00 | 10.67 |
| 2×6 | 8.00 | 10.00 | 12.00 | 16.00 |
| 2×8 | 10.67 | 13.33 | 16.00 | 21.33 |
| 2×10 | 13.33 | 16.67 | 20.00 | 26.67 |
| 2×12 | 16.00 | 20.00 | 24.00 | 32.00 |
| 4×4 | 10.67 | 13.33 | 16.00 | 21.33 |
Then cut it
Board feet tell you how much lumber to buy. To know which boards and how to cut them, put your cut list into the lumber cutting calculator for lengths, or the cut list optimizer for plywood and sheet goods. There are worked project cut lists for a bookshelf, workbench, cabinets and more.
Questions
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