Calculating Wood Volume

The Calculation

In the simplest of terms, wood volume is expressed in board feet, one being a board 12” wide by 1” thick by 12” long. So we can extend this to any board size or stack of boards.   If you multiply a board’s width in inches, by the board’s thickness in inch by the board’s length in inches, you get the total number of cubic inches off volume of the board.  Divide that number by 144 (the number of cubic inches in a board foot) and you get the number of board feet that makes up a board.  So, in summary, board feet can be represented by:

Rectangular Determination

We determine your cost of drying based on the volume you wood takes up in the kiln. For sawn lumber boards or timbers, this is straight forward, based on the formula above. However, for live edge slabs, and rounds (otherwise known as “cookies”) that occupy volume in the kiln, and displace lumber, we must determine their volume as if they were a rectangle.  Most slabs have tapered or curved widths, so we determine their size based on the straight sided lumber their irregular shape will displace.

• In the case of a tapered width slab, the widest point x the greatest thickness x the longest length gives us the rectangular volume.
  
• In the case of a bent log slab, it’s a little more tricky, but imagine a square box the bent slab will fit in and calculate those measurements

An Example

1. A board 1.5” thick x 10” wide x 16-1/2’ long    (a 16-1/2 foot long board (x12”/foot) is also 198” long)  
2.  1.5 x 10 x 198 = 2970 cubic inches 
3.  Divide by 144 to get board feet, so 2970 / 144 = 20.6 board feet
4.  If the board foot drying cost of this species of wood is $0.65 per board foot, then 20.6 x $0.65 = $13.39 total  

Kitsap Dry Kiln will be happy to quote your total volume of lumber in board feet and a total drying cost based on the total volume x the board foot drying cost.