Lumber sizes chart: nominal vs. actual
Boards are named by their rough size before drying and planing. By the time you buy them, they're smaller. Here are the actual sizes of common softwood boards, and what hardwood "quarter" thicknesses mean.
Common boards
1x2¾ x 1½ in
1x3¾ x 2½ in
1x4¾ x 3½ in
1x6¾ x 5½ in
1x8¾ x 7¼ in
1x10¾ x 9¼ in
1x12¾ x 11¼ in
2x21½ x 1½ in
2x41½ x 3½ in
2x61½ x 5½ in
2x81½ x 7¼ in
2x101½ x 9¼ in
2x121½ x 11¼ in
4x43½ x 3½ in
Hardwood thickness in quarters
| Called | Rough thickness | Typical after surfacing |
|---|---|---|
| 4/4 | 1 inch | about ¾ to 13/16 inch |
| 5/4 | 1¼ inches | about 1 to 1 1/16 inches |
| 6/4 | 1½ inches | about 1¼ to 1 5/16 inches |
| 8/4 | 2 inches | about 1¾ inches |
Typical US sizes for dry, surfaced lumber. Actual sizes can vary slightly, and lengths are usually a little over the stated length. Always measure the board you have before cutting.
At the lumber store
Sight it
Look down the length for bows and twists.
Check ends
Avoid splits and big knots near the ends.
Bring a list
Your cut list with actual sizes.
Buy extra
10 to 20% more for mistakes.
Read lumber sizes explained and choosing wood, or price your boards with the board foot calculator.