The document lists standard lumber sizes used in construction. It notes that lumber is specified by its nominal size, which is larger than the actual dimensions. For example, a nominal 2x4 actually measures 1 1/2 inches by 3 1/2 inches. The chart provides the nominal and actual thickness and width for common wood board sizes ranging from 1x2 to 6x6.

1. STANDARD LUMBER SIZES
Standard Lumber Sizes
Nominal Size
Actual Size
1x2
¾” x 1 ½”
1x4
¾” x 3 ½”
1x6
¾” x 5 ½”
1x8
¾” x 7 ¼”
1 x 10
¾” x 9 ¼”
1 x 12
¾” x 11 ¼”
2x2
1 ½” x 1 ½”
2x4
1 ½” x 3 ½”
2x6
1 ½” x 5 ½”
2x8
1 ½” x 7 ¼”
2 x 10
1 ½” x 9 ¼”
2 x 12
1 ½” x 11 ¼”
4x4
3 ½” x 3 ½”
4x6
3 ½” x 5 ½”
6 x 6*
5 ½” x 5 ½”
Board lumber is specified by the
nominal (in name only) size.
Example:
1x6 1x8 2x4 2x6 2x8
Nomimal sizes are larger than actual
sizes.
Nominal size 2 x 4, actual size, 1 ½ x 3 ½”
**Always layout for the actual dimension of
the lumber!
Standard sizes of lumber are always
shown thickness before width.
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