How to Convert Square Foot to Board Foot

A board foot is a unit used for measuring the volume of lumber. A single board foot is equal to the volume of a piece of wood that measures one foot long, one foot wide, and one inch thick. This is equal to 144 cubic inches. The one foot by one foot by one inch board is a nominal size for the standard of the measurement. Board feet can be applied for measuring the volume of any size of lumber. The number of board feet of wood needed to cover a surface area can be calculated. This is done by use the square foot surface area and approximate thickness of the wood.

Step 1

Determine what thickness of board will be used over the surface area. The nominal thickness for board feet is one inch, but a different thickness can be used where needed. This measurement will almost always be provided in inches because that is the standard used by most lumber companies for thickness.

Step 2

Divide the thickness of board by 12 to convert it from inches to feet.

Step 3

Multiply the surface area in square feet by the board thickness in feet. This will give the quantity of board feet needed to cover that area.