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Jeff Bryant

Compute Dimensional Lumber Sizes, Volume of Lumber

May 3, 2012 —
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Since its creation, Wolfram|Alpha has constantly grown to cover more and more topic areas. Now, it includes some functionality that may be useful for people interested in lumber. Most of us are used to going into a local home improvement store and seeing large collections of construction lumber, but before it gets into those stores, it has to be cut from logs. An important step in the process is determining how much lumber can be obtained from a log of a given size. There is no single method for estimating this, but there are a number of empirical formulas that are commonly used to estimate the volume of lumber that can be obtained from a log given its diameter and length. Typically, these estimates are rounded to the nearest 5 or 10 board feet. Three of the most common empirical rules are the Doyle Rule, the Scribner Rule, and the International 1/4-inch log rule. Different regions tend to use different rules, so it’s up to users to decide which one they want to use.

Doyle's log rule

Scribner's log rule

International 1/4 inch log rule

Going back to the home improvement store, we are presented with the large stacks of construction lumber. Typically, construction lumber is made from softwoods like pine or fir. These are cheaper and lighter than hardwoods like oak, and so it’s uncommon to find something like a 2x4 made of oak. The exact type of wood used to make construction lumber varies depending on where you live, typically favoring what is abundant and affordable in your area.

When you buy a 2x4 or other related piece of dimensional lumber, you are actually getting less than you might think. In today’s world, a 2x4 is only a 2x4 when it’s rough cut from a log. After finishing and drying, these boards will shrink. By the time you buy this from your local store, it is smaller than its rough cut size. Wolfram|Alpha includes information on both the original, nominal, and actual size you find in the store. Combined with the knowledge Wolfram|Alpha already has about types of wood, we can compute things like weight ranges based on the families of wood being used.

2x4 lumber

You can also vary the length and wood type as desired.

2x4x10 fir

While Wolfram|Alpha can’t do the carpentry work for you, it can help you understand exactly what you need to do the job.


i never seen before like this its really awesome !!!

Posted by Mehul Kanani May 5, 2012 at 12:02 am

So awesome! Please keep adding these things to wolfram.

Posted by Abraham Borg May 5, 2012 at 8:32 am

Is this a natural log?

Posted by Marq March 6, 2014 at 6:34 pm

amei, muito fácil de usar, porem só faltou ser traduzido para o Português

Posted by Thiago December 1, 2014 at 11:11 am