Board Foot Calculator
Enter the lumber size and quantity to get total board feet and what the order will cost.
Results are estimates for planning only. Always confirm measurements, local codes and manufacturer specs before ordering materials or quoting a job. See our Terms.
What is a board foot?
A board foot is a volume of wood 1 inch thick, 12 inches wide and 12 inches long (144 cubic inches). Board feet = thickness (in) x width (in) x length (ft) / 12.
Hardwood is usually sold by the board foot using nominal rough thickness (4/4 = 1 in, 8/4 = 2 in). Dimensional softwood like 2x4s is normally priced per piece or per linear foot.
Questions
How many board feet in a 2x4x8?
2 x 4 x 8 / 12 = 5.33 board feet (using nominal size).
How do I calculate the cost of lumber by the board foot?
Multiply total board feet by the price per board foot. 20 boards of 2x6x8 at $1.50 per board foot is 160 board feet, or $240.
Do I use actual or nominal dimensions?
Lumber yards almost always use nominal dimensions for board-foot pricing, so a 2x6 counts as 2 x 6 inches.