A board foot calculator is a tool that calculates volume. Board feet is typically used in the sale of lumber. A board foot is equal to 144 cubic inches.
A board foot isn't a cubic foot but a 12-inch-by-12-inch piece that is 1 inch thick. It is also important that in this calculation the initial, or roughsawn, thickness is used to find the volume. A piece of 4/4 lumber is approximately 3/4 of an inch thick after it has been surfaced and smoothed, but it is not 0.75 board feet; it is one board foot. Consequently, one board foot of 8/4, or 2-inch roughsawn lumber actually has more wood than a board foot of 4/4 lumber, as the 4/4 has more surface area than the 8/4 to be smoothed, while both have the same initial volume.