Board Foot Lumber Calculator

CALCULATE = Enter Your Board Thickness, Width & Length in the proper fields below.
Board Thickness:  
Board Length:
Board Width:  
Board Feet

How to Calculate Board Feet

  1. What is a Board Foot? A Board Foot is 144 cubic inches of rough lumber. This is a volume measurement, the same as a gallon or liter. Those cubic inches can be arranged any which way: they can be spread way out (e.g. 12" x 12" x 1") or compacted (6" x 6" x 4").


    2.
  2. How do I calculate Board Feet? The National Hardwood Lumber Association has defined this calculation in two stages, as follows:
    1. Width (in inches) x Length (in feet) Divided by 12 = Surface Measure.


    2. Surface Measure x Thickness = Board Feet. Generally speaking, surface measure should be rounded to a whole number, before multiplying it by thickness. (This rule gets exceptions when lumber gets really expensive, as in rare and exotic species.) Examples: a board 1" thick x 6" wide x 8' long: 6" x 8' = 48 divided by 12 = 4. So 4 is the surface measure. Times 1 = 4. So that board is 4 board feet. A board 2" thick x 4" wide x 10' long: 4 x 10 = 40 divided by 12 = 3.33. Rounded to 3 is your surface measure. Times 2 = 6 board feet. (Notice that if you didn't round off the 3.33 you would get a board footage of 6.66 which would round to 7.)
image