Enter your lumber dimensions to get board feet per piece, total board feet, and cost.
Estimates only.
A board foot is a unit of lumber volume equal to 144 cubic inches: a piece 1 inch thick, 12 inches wide and 12 inches long. The formula is thickness (in) times width (in) times length (ft), divided by 12.
Use nominal thickness for rough lumber (a "1 inch" board is counted as 1 inch even if it measures thinner after surfacing). For thick stock, lumber is often sold in quarter-inch units, so 4/4 means 1 inch, 8/4 means 2 inches.
Multiply thickness in inches by width in inches by length in feet, then divide by 12. For example, a 2 inch by 6 inch by 8 foot board is (2 x 6 x 8) / 12 = 8 board feet.
A board foot is 144 cubic inches of lumber: one inch thick, one foot wide, and one foot long. It is a measure of volume, not surface area.
A nominal 2x4 that is 8 feet long is (2 x 4 x 8) / 12 = about 5.33 board feet, using nominal dimensions.
Board feet measure the actual volume of wood, so hardwoods and thicker stock are usually priced per board foot rather than per piece, which makes different sizes comparable.