Nominal vs. Actual Dimensional Lumber Sizes
In North America, framing lumber is designated by nominal dimensions (the size before drying and surfacing). This chart provides exact actual dress dimensions for jobsite layout.
| Nominal Size | Actual Size (Inches) | Actual Size (mm) | Board Feet per 8ft Board |
|---|---|---|---|
| 1 x 4 | 3/4" x 3-1/2" | 19 x 89 mm | 2.67 BF |
| 2 x 4 | 1-1/2" x 3-1/2" | 38 x 89 mm | 5.33 BF |
| 2 x 6 | 1-1/2" x 5-1/2" | 38 x 140 mm | 8.00 BF |
| 2 x 8 | 1-1/2" x 7-1/4" | 38 x 184 mm | 10.67 BF |
| 2 x 10 | 1-1/2" x 9-1/4" | 38 x 235 mm | 13.33 BF |
| 4 x 4 | 3-1/2" x 3-1/2" | 89 x 89 mm | 10.67 BF |