Put simply, the board foot calculation is how lumber yards stay in business. And it is the custom as well as legal.
Width is usually the next higher inch and boards are measured individually. Two boards 5-1/2" wide are considered 6 inches each thus a foot is used to calculate.
Length is usually to the next foot. Anything more than 3 inches over the foot, is the next foot.
The thickness is 1 for everything one inch or less. Thickness is usually 4/4, 6/4, 8/4 and 12/4. ( 1, 1-1/2, 2 and 3) The next higher x/4 is almost always used. Thus 5/4 is charged as 6/4. The other thing to remember is that if 4/4 is $1 a board foot, then 6/4 is probably $2, 8/4 is $3.50 and 12/4 is probably $5, ALL PER BOARD FOOT. In other words, the thicker the board, the higher price per board foot.
Width is usually the next higher inch and boards are measured individually. Two boards 5-1/2" wide are considered 6 inches each thus a foot is used to calculate.
Length is usually to the next foot. Anything more than 3 inches over the foot, is the next foot.
The thickness is 1 for everything one inch or less. Thickness is usually 4/4, 6/4, 8/4 and 12/4. ( 1, 1-1/2, 2 and 3) The next higher x/4 is almost always used. Thus 5/4 is charged as 6/4. The other thing to remember is that if 4/4 is $1 a board foot, then 6/4 is probably $2, 8/4 is $3.50 and 12/4 is probably $5, ALL PER BOARD FOOT. In other words, the thicker the board, the higher price per board foot.
