How to measure your lumber?
What is a Board Foot?
It's strange, but easy!
When you're looking at a stack of hardwood lumber and and you begin picking out the boards you like and want to buy, you'll notice that each board has a different width (W), and possibly a different length (L).
Let's say you've found two pieces in the 4/4 stack, one is 8" x 96" and the other is 4" x 96". Should you pay the same price for both pieces? No way! The first board has twice the amount of wood in it (it's twice as wide and the same length)!
The unit of measurement for this kind of lumber, then, is the board foot. It's a measure of the volume of wood that's in a board.
To find the volume of wood, or the number of board feet, simply use this formula.
Notice that each measurement - thickness, width and length - are in inches, then divided by 144. You can also come to the same end by measuring just the length in feet, and dividing by 12 instead.
CALCULATING BOARD FEET
A board foot is the standard industry measure of wood measuring 12”x 12” by 1” thickness. Usually only lumber is sold in board feet.
Equation: Board Feet = rough width x rough thickness / 12”
Example: A beam measuring 4”x 6”x 10’ is 4”x 6” / 12” x 10’ = 20 Board Feet
CALCULATING SQUARE FEET
This is the amount of material required to cover one square foot of wall or floor space, disregarding the thickness of the material.
Equation: Square Feet = width x length of space (wall or floor)
Example: A room measuring 12’x 15’ is 12’x 15’ = 180 Square Feet
Elmwood uses the “finished width” of flooring to figure square feet. Actual face widths vary from the width of the floor. For example, a 9” width floor will have an actual face width of 8-1/2”.
OTHER USEFUL INFORMATION
Area of a triangle = ½ base x perpendicular height.
Area of a circle = π (3.14) x radius squared or diameter squared x .7854.
Area of a square = length x width.
Length of one side of a square x 1.128 = the diameter of an equal circle.
The capacity of a pipe = diameter squared (in inches) x the length (in inches) x .0034. Doubling the diameter of a pipe or cylinder increases its capacity 4 times.
Board Feet - Lumber thickness 1"
Quick Approximation for Calculating Board Feet
- 1 x 4 - divide linear length (feet) by 3 - (length x 1/3)
- 1 x 6 - divide linear length (feet) by 2 - (length x 1/2)
- 1 x 8 - multiply linear length (feet) by 0.66 - (length x 2/3)
- 1 x 12 - linear length (feet) equals board feet - (length x 1)
- 2 x 4 - multiply linear length by 0.66 - (length x 2/3)
- 2 x 6 - linear length (feet) equals board feet - (length x 1)
- 2 x 8 - multiply linear length by 1.33 - (length x 1 1/3)
- 2 x 12 - multiply linear length by 2 - (length x 2)