If you’ve ever tried to buy hardwoods from a lumber store you’ve likely heard the term “board foot” as in “We sell by the board foot.” Okay, great!…What the hell does that mean? Let me back up and try and explain it to you.
When you step foot into Home Depot or Lowe’s and want to buy a piece of lumber, let’s say a typical 2x4x8 for example, there’s a sticker or sign right on the aisle that tells you the price per piece. You know exactly how much that piece costs (+ tax) when you get to the register. That’s because softwoods (pine family, etc) or construction grade lumber is what’s called Dimensional lumber. Dimensional lumber is exactly as it sounds, a piece of wood of a certain dimension (2″ x 4″….well actually 1.5″ x 3.5″ but still) by a certain length (8′ in our example). The dimensions of this type of lumber are standardized for construction purposes and common in any typical construction type of softwood. You are paying for that Dimension of lumber by the Linear foot. So at 8 ft long a 2×4 costs somewhere in the range of $2. When you move up to 10 ft long the 2×4 costs closer to $3.50-$4. Get what I’m saying? You’re paying by the linear foot. The longer the board, the more expensive it is.
Board feet is a little bit different and typically applies to hardwoods (oak, walnut, maple, cherry, etc). It is a volume measurement of the wood. The simplest way to define a board foot = 1 sq. ft of board at 1″ thick. So 1″ of thickness x 12″ length x 12″ width. 1 board foot is equal to 144 cubic inches. A lumber retailer might have a price listed next to a bunch of seemingly random (usually not random but we’ll go into that another time) cut pieces of Walnut for example at $5.99/ board foot (just an example). Rather than taking it up to the register and being shocked by how much it costs, say you want to know before you get there. If the retailer is nice, they might have already written the board feet total on the particular piece in chalk so you can just multiply that number by the cost per board foot, but more often than not they don’t.
Say a piece of walnut is 4″ thick x 8″ wide x 6′ long and the retailer is charging $5.99/bf. How can we determine the board foot total and thus the cost of that piece? Well the best way to do it is like this.
4″ x 8″ x 72″ (6 ft) = 2,304 cubic inches divided by 144 cu. inches (1 board ft) = 16 board feet
16 bf x $5.99 = $95.84
Okay that’s all great but when would this apply to you? Well it only really applies to you if you’re going to try to get into woodworking or maybe you just feel like making something out of hardwood. Maybe you’d like to try and make a cutting board and you read that hardwoods like maple are the best type of wood for that. Or maybe you just want to see if something on Etsy is seemingly reasonably priced given the type of wood used and how big it is. Understanding how it’s priced is half the battle, and just keep in mind that hardwoods are EXPENSIVE!