Lumber Sizes

About Lumber Sizes

Lumber is customarily referred to by nominal sizes such as 1x6, 2x4, 4x4 and so forth. In these descriptions, the first number represents the thickness; the second number represents the width. The practice is based upon the size of the rough piece that is sawn from logs at the sawmill.

It is important to note that what we call 2x4 or 1x8 is usually a piece of lumber smaller than its nominal size. This is because lumber has a tendency to shrink as it dries. Most lumber is planed to make it smooth, which further reduces its size.

The table below lists nominal lumber sizes and shows the corresponding actual (or net) size. Please treat this as a guide only. Exceptions exist. If you require the net size of a particular item, please give us a call!

 

THICKNESSES · WIDTHS
Nominal Actual · Nominal Actual
1/2" 1/2" · 2 1-1/2” – 1-3/4”
5/8” 5/8” · 3 2-1/2” – 2-3/4”
1” 3/4" · 4 3-1/2”
5/4” 1-1/16” · 5 4-1/2”
2” 1-1/2” · 6 5-1/2”
4” 3-1/2” · 8 7-1/4”
6” 5-1/2” · 10 9-1/4”
· · · 12 11-1/4”