Board Foot Calculator

A board foot is a unit of lumber volume equal to 144 cubic inches. It's the standard way hardwoods are sold in the United States. One board foot is a piece of lumber 1 inch thick, 12 inches wide, and 12 inches long, or any other combination of dimensions that adds up to 144 cubic inches.

Multiply thickness (in inches) by width (in inches) by length (in inches), then divide by 144. For multiple boards of the same size, multiply the result by the quantity.

For example, a 1-inch by 6-inch board that's 8 feet long (96 inches) is 4 board feet. Ten boards that size is 40 board feet.

Linear feet measures length only. Board feet measures volume, so it accounts for thickness and width too. A 1-inch by 6-inch board and a 2-inch by 12-inch board can both be 8 linear feet long, but the bigger board contains four times the volume of lumber.

Hardwoods are usually sold by the board foot. Softwood dimensional lumber (studs, joists) is often sold by linear foot.

Lumber is measured in mixed units in the field. A board might be 8 feet 4 inches long, or 12 feet 6 inches. Splitting the length into feet plus inches lets you enter measurements the way you actually take them, without converting to decimal feet or total inches first.

Sometimes you know how much lumber you need (in board feet), and you need to figure out how many boards to buy at a given size. Find Quantity does that math in reverse: enter the board dimensions and your target board feet, and the calculator returns the number of boards needed and the overage you'll end up with.

Useful when buying lumber to a budget or when the supplier sells in fixed quantities.