What is boardfoot?
A board 1 inch thick and 12 inches square is 1 board foot. Any
combination of these measurements is 1 board foot. A board 2 inches
thick, 6 inches wide and 12 inches long is 1 board foot.
For instance, to calculate the board feet in a beam that
measures 6" wide x 8" high x 10' long the formula is 6x8x10/12=40
bf .
Likewise, a 2"wide x 10" high x 10' long piece of lumber is
calculated 2x10x10/12=16.66 bf.
So a 1x12x12 would calculate 1x12x12/12=12 bf.
All board footage is calculated on rough dimensions, so even
though a 2x10 S4S measures only 1 1/2"x 9 1/4" the board footage is
calculated by multiplying 2 times 10 times the length divided by
12.