How board feet are worked out
A board foot is 144 cubic inches: a board 1 inch thick, 12 inches wide and 1 foot long. Multiply the thickness and width in inches by the length in feet and divide by 12. A 2x6 that's 8 feet long is 2 × 6 × 8 ÷ 12 = 8 board feet.
Board feet = thickness (in) × width (in) × length (ft) ÷ 12Board feet = thickness × width × length, all in inches, ÷ 144Cubic feet = board feet ÷ 12Board feet in common pieces
| Piece | Board feet |
|---|---|
| 1x6, 8 ft | 4 |
| 2x4, 8 ft | 5.33 |
| 2x6, 8 ft | 8 |
| 2x8, 10 ft | 13.33 |
| 2x10, 12 ft | 20 |
| 2x12, 16 ft | 32 |
| 4x4, 8 ft | 10.67 |
| 6x6, 10 ft | 30 |
Which size to enter
Enter the size the lumber is priced by. Framing lumber is called by its nominal size, the 2x6 in its name, and hardwood thickness is named in quarters of an inch: 4/4 is 1 inch, 5/4 is 1 1/4 and 8/4 is 2. If the yard quotes a price per board foot, ask which size it figures from.
Common questions
How many board feet in a 2x4x8?
5.33 board feet: 2 × 4 × 8 ÷ 12.
What is a board foot?
144 cubic inches of wood: 1 inch thick, 12 inches wide and 1 foot long.
How many board feet are in a cubic foot?
Twelve. A cubic foot is 1,728 cubic inches, and 1,728 ÷ 144 = 12.
How do I price lumber by the board foot?
Multiply the board feet by the price per board foot. Enter the price above and the calculator does it; for a whole job with labor, overhead and profit, an estimate lists the lumber as its own line.