Lumber Size



Nominal Size - is the size of a piece of lumber before it is dressed and seasoned. It is used to designate a particular size piece of lumber, such as 2x4, 2x6, etc.

Actual Size - refers to minimum acceptable size after it has been dressed and seasoned. A nominal 2*4 can have a minimum actual size of 1.5" x 3.5". When referring to a specific piece of lumber, the nominal size is used.

Size Chart

Framing Lumber


Nominal Size
Actual Size
2 x 2
1 1/2 x 1 1/2
2 x 3
1 1/2 x 2 1/2
2 x 4
1 1/2 x 3 1/2
2 x 6
1 1/2 x 5 1/2
2 x 8
1 1/2 x 7 1/4
2 x 10
1 1/2 x 9 1/4
2 x 12
1 1/2 x 11 1/4
4 x 4
3 1/2 x 3 1/2
4 x 6
3 1/2 x 5 1/2
4 x 10
3 1/2 x 9 1/4
6 x 6
5 1/2 x 5 1/2

Boards


Nominal Size
Actual Size
1 x 2
3/4 x 1 1/2
1 x 3
3/4 x 2 1/2
1 x 4
3/4 x 3 1/2
1 x 5
3/4 x 4 1/2
1 x 6
3/4 x 5 1/2
1 x 8
3/4 x 7 1/4
1 x 10
3/4 x 9 1/4
1 x 12
3/4 x 11 1/4