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How To Speak Hardwood (measurements)

Updated: May 23

So you have decided on your next project—great! You’ve even decided on the

type of wood you’re going to use—perfect. You have your measurements written down as well… Sounds like you’re ready! You excitedly pull up the Hardwood Lumber and Millwork website to see if they have your select wood in stock and… What’s this? 6/4? 8/4? Charged by the BF? What does this all mean? Before you get intimidated, check out this information. You’ll be speaking like one of the regulars and can walk in with confidence! And if you forget something, don’t worry. We’ll help you through it!



As you may already know, thickness refers to the measurements from the face of the board to the back side of the board. In the world of lumber, this is shown as a fraction with the denominator (bottom number) staying as a four and the numerator (top number) being dependent on the actual measurement.

For example:

A quick history lesson that’s actually pretty cool… in a wood-nerd sort of way.

Why is hardwood measured in quarters, you ask? Back in the day, sawmills were set up to change the board thickness in quarter-inch jumps. Four pulls on the lever equaled four quarter-inch increments, or one inch, AKA 4/4. Five pulls equaled 1-1/4”, or "five quarters." We still use that system today!

Board Foot

Thickness can be figured up pretty easily with just our fingers. The next unit of measurement will require the use of a calculator! Board foot, or BF, is a way for lumber mills to calculate the amount of wood in rough stock. As you already know, wood does not come from a tree in a perfect rectangle (wouldn’t that be nice?). Think of BF as a measure of the volume of the board to help you understand the equation. You’ll want to multiply the thickness x height x length. Easy right? You’ll then take that number and divide it by 144. This number will be the size of your board in board feet!


Let’s try a simple example:

We have a board that is 1.5” in thickness, 6.25” in width, and 96” in length. So 1.5x6.25x96. We multiply those three numbers to get 900. Now let’s divide 200 by 144” (one square foot) to get ~6.3 BF.


Easy! This will help when budgeting a project to understand how much lumber you will need, and how much it will cost. Pro-tip: Buy at least 30% more than what you expect to use to account for waste and cut-offs! No one likes the drive of shame to go pick up more lumber, unless you want an excuse to look around more!



The bottom line is that you can vastly improve your confidence in ordering lumber by understanding these simple, albeit unique, ways of measuring lumber. Our goal here at Hardwood Lumber and Millworks is to build your confidence as you grow in your journey of woodworking! And remember, if you’re still unsure you can always reach out to us at We would love to hear from you and assist in your next lumber purchase!

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