Three ways lumber is priced
- Per piece. Common for construction lumber such as 2x4s, 2x6s and 4x4s sold at a home center.
- Per linear foot. Common for trim, molding and some deck boards.
- Per board foot. The unit of hardwood and rough lumber, and the best way to compare different sizes and lengths.
Board feet = thickness (in) × width (in) × length (ft) ÷ 12
Price per board foot = price per piece ÷ board feet per piece
The calculation uses the nominal size, because that is how lumber is priced. A 2x4 that is 8 ft long is 2 × 4 × 8 ÷ 12 = 5.33 board feet. If the piece costs $4.00, that is $0.75 per board foot and $0.50 per linear foot, and ten pieces cost $40.
Why compare per board foot?
A price per piece hides the size. A $9 2x6x8 and a $13 2x6x12 look very different, but both are about the same per board foot: $9 ÷ 8 = $1.13 and $13 ÷ 12 = $1.08. The one with the lower figure gives you more wood per dollar. Longer boards often cost less per foot, but only if you can use the length without waste.
Board feet in common pieces
| Size | 8 ft | 10 ft | 12 ft | 16 ft |
|---|---|---|---|---|
| 2x4 | 5.33 | 6.67 | 8.00 | 10.67 |
| 2x6 | 8.00 | 10.00 | 12.00 | 16.00 |
| 2x8 | 10.67 | 13.33 | 16.00 | 21.33 |
| 2x10 | 13.33 | 16.67 | 20.00 | 26.67 |
| 2x12 | 16.00 | 20.00 | 24.00 | 32.00 |
| 4x4 | 10.67 | 13.33 | 16.00 | 21.33 |
| 6x6 | 24.00 | 30.00 | 36.00 | 48.00 |
Rough hardwood quotes follow the same rule with the thickness taken from the quarter system: 4/4 is 1 inch, 8/4 is 2 inches. For a stack, or for a hardwood project with waste, use the board foot calculator. Sizes and their real dimensions are on the lumber dimensions chart, and what a board foot is explains the unit.
Frequently asked questions
How do I find the price per board foot of a 2x4?
Divide the price by the board feet in the piece. A 2x4x8 is 5.33 board feet, so a $4 board is $0.75 per board foot.
How many board feet are in a 2x4x8?
5.33, using the nominal size. A 2x4x12 is 8 and a 2x4x16 is 10.67.
Is it cheaper to buy lumber by the board foot?
Not necessarily. It is a way to compare quotes. Piece prices at a store can be lower per board foot than a mill's price for the same wood.
Sources
Reference charts
More lumber and wood calculators
Board Foot Calculator
Board feet and cost for any stack of lumber.
Plywood Calculator
Sheets of plywood or OSB for floors, walls and roofs.
Stud Calculator
Studs and plates for any wall.
Firewood Cord Calculator
Check a woodpile in cords and face cords.
Log Weight Calculator
Green weight and Doyle board feet by species.
Log Board Foot Calculator
Board feet in a log by two log rules.