Welcome to: Calculating board feet. Hardwood lumber is sold by the board foot.
One board foot equals 144 cubic inches or the equivalent of one
piece of wood one inch thick by 12 inches wide by 12 inches long.
Most hardwood comes in four quarter, five quarter, six quarter, and eight quarter thicknesses.
Board footage can be calculated by either one of the following formulas:
thickness x width x length divided by 144, or thickness x width x length divided by twelve.
Using the formula: thickness x width x length divided by twelve, the above 4 x 4 board would
be 1 x 8 x 8 divided by 12 or 5.3 board feet. Likewise, if that same board was 1 1/4 inches
thick or 5/4 lumber, the equation would be 1.25 x 8 x 8 divided by 12 which equals 6.7 board feet.
now what have you learned? Now we'll test what you have learned with a few questions.
Calculate the board feet for the following piece.
The correct answer is five board feet.
Very good! Let's try another. Calculate the board feet for this piece.
The correct answer is 4.5 board feet.
Board footage is usually rounded off to the nearest whole number. In the preceding example
the board contained 4.5 board feet. Most lumber dealers would count that board as having 5
board feet. Now try this example. Remember that the formula for measuring lengths in
inches is thickness x width x length divided by 144 and that the board feet total should
be rounded to the nearest whole number. So calculate the board feet for this piece.
The answer rounded to the nearest whole number is 4 board feet.
Now let's review. True or false: hardwood lumber is sold by the board foot.
The answer is true.
True or false: lumber dealers typically round off board feet to the nearest one tenth of a foot.
The answer is false.
True or false: one board foot is equal to a piece of wood one inch thick by 12 inches wide by 12
inches long. The answer is true. Here are a few strategies for calculating board feet. Measuring
individual boards can be a time-consuming process. One method which can be used to
speed the process is to lay boards side by side and measure the overall width, so in this example,
the calculation would be 1 x 36 x 8 divided by 12 which equals 24 board feet. Another method
for calculating board feet quickly and accurately is to use a special tool called the board rule.
So in review, calculating board feet footage is simple with either of these two formulas.
Now that you know the process, try practicing on some actual samples.
This completes this learning object: Calculating board feet.