How to calculate BFT

Before you start any project you have to calculate the materials needed. Wood is calculated in board feet,(BFT) it is important to be able to convert the dimensions you need into board feet to ensure you have the proper quantity of wood to complete your project.

1 BFT = 144 cubic inches or the equivalent.

Formulas

BFT = [thickness (in) x depth (in) x length (ft)] ÷ 12 feet
or
BFT = [thickness (in) x depth (in) x length (in)] ÷144 inches

Examples

  1. Determine the board's dimensions.

    Example 1 : 1 in x 6 in x 8 ft
    Since the desired thickness is 1 in, 4/4 boards will be necessary. (4/4 = 1 gross inch)

    Example 2 : 2 in x 6 in x 12 ft
    Since the desired thickness is 2 in, 8/4 boards will be necessary. (8/4 = 2 gross inches)

  2. Convert the dimensions into BFT with the formula.

    Example 1 : 1 in x 6 in x 8 ft
    [1 in x 6 in x 8 ft] ÷ 12 ft = 4 BFT

    Example 2 : 2 in x 6 in x 12 ft
    [2 in x 6 in x 12 ft] ÷ 12 ft = 12 BFT

  3. Multiply the number of BFT by the BFT retail price.

Wood thickness guide

4/4 =    1" gross =    3/4" net
5/4 =    1 1/4" gross =    1" net
6/4 =    1 1/2" gross =    1 1/4" net
8/4 =    2" gross =    1 3/4" net
10/4 =    2 1/2" gross =    2 1/4" net
12/4 =    3" gross =    2 3/4" net
16/4 =    4" gross =    3 3/4" fini