Lumber calculations can be confusing, even for veteran woodworkers. At Rockler Woodworking and Hardware, we make every effort to simplify the process. Below, we'll go over some of the most common methods for pricing lumber, explain Rockler's method for calculating the cost of lumber, and introduce our time and calculation saving Lumber/Veneer Configurator.
Common Methods for Pricing Lumber
Lumber is usually sold in one of three ways: by the piece, by the lineal inch, or by some method based on the square foot dimensions of the lumber being sold.
Buying lumber by the piece is something that most of us are familiar with. The lumber is cut to a specific size in all three dimensions, and sold at a set price. At Rockler, we price lumber by the piece when it makes the most sense to do so. Turning stock in common sizes is priced by the piece, for example.
The "lineal inch" method of pricing lumber is also simple and familiar. Lumber sold by the lineal inch is cut to a specific width before it is offered for sale. The price is determined by the length of the material being purchased. A 12' long hardwood board priced at $.20 per lineal inch costs .20 x 12 = $2.40. Rockler sells much of it "dimension lumber" by the lineal inch. The stock is planed smooth to a specific thickness, cut to a specific width, and then sold at a price per inch for sizes ranging from 6 to 60 inches.
"Random-width lumber" is not cut to a specific width before it is sold. As the name implies, the width of boards sold as random-width lumber varies. Woodworkers who buy random-width lumber cut the lumber to width themselves, and understand that some amount of waste will be generated in the process.
A pricing system for random-width lumber has to take the varying widths of the boards into account. The most common method of pricing random-width lumber is by the "board foot." Board feet are calculated by multiplying the surface area of the lumber (measured in square feet) by the thickness of the lumber (measured in inches).
A board that's 1" thick, 12" wide and 24" long is:
(1 foot wide) x (2 feet long) x (1 inch thick) = 2 board feet of lumber.
A board that's 2" thick, 12" wide and 24" long is:
(1 foot wide) x (2 feet long) x (2 inches thick) = 4 board feet of lumber.
How Rockler Prices Lumber
Rockler's method of pricing random-width lumber differs slightly from the "board foot" method described above. The main difference is simply that the "thickness factor" is taken out of the equation. In other words, Rockler calculates the best price possible for each thickness of a given species of random-width lumber and prices the lumber based strictly on it's square-foot dimensions.
Ordering Lumber from Rockler
To order lumber from the Rockler website, simply follow the instructions in the lumber offer. Each lumber offer is linked to the Rockler Lumber/Veneer Configurator, which calculates the cost of the lumber you order based on the dimensions you supply. Please remember that requests for specific widths of random-width lumber are subject to availability.
Calculating the Cost Yourself
Even though our lumber configurator does all of the calculations necessary for lumber orders, we know that some woodworkers prefer to do the math themselves before they place an order. Here's how to calculate the cost of your order:
The number of square feet of a piece of lumber is calculated by multiplying the length (in inches) by the width (in inches) and then dividing by 144.
Example: Calculating the total cost of a piece of lumber 6" wide by 46" long at a price of $6.30 per square foot.
First, multiply the width by the length to determine the number of square inches:
6 x 46 = 276 square inches.
Next, determine the number of square feet by dividing total square inches by 144:
276/144 = 1.917 square feet.
Then, round the result to the nearest tenth of a square foot:
1.917 rounded to the nearest tenth = 1.9 or 1-9/10 square feet.