(Width (in inches) * Length (in feet) * Thickness (in inches)) /12
. 1 Board foot is equal to a 12" x 12" piece of material 1" thick. Try the board foot calculator below!
(D-4)2 * (L /16)
0.04976191 * L * D2 + 0.006220239 * L2 * D - 0.1854762 * L * D + 0.0002591767 * L3 - 0.01159226 * L2 + 0.04222222 * L
(.79D2 -2D -4)L/16