Lumber Size Chart
Use this lumber size chart to compare common nominal lumber sizes with their actual dimensions in inches and millimeters.
Common Lumber Sizes
| Nominal Size | Actual Thickness | Actual Width | Approx. Metric Size |
|---|---|---|---|
| 2x2 | 1.5 in | 1.5 in | 38 × 38 mm |
| 2x3 | 1.5 in | 2.5 in | 38 × 64 mm |
| 2x4 | 1.5 in | 3.5 in | 38 × 89 mm |
| 2x6 | 1.5 in | 5.5 in | 38 × 140 mm |
| 2x8 | 1.5 in | 7.25 in | 38 × 184 mm |
| 2x10 | 1.5 in | 9.25 in | 38 × 235 mm |
| 2x12 | 1.5 in | 11.25 in | 38 × 286 mm |
| 4x4 | 3.5 in | 3.5 in | 89 × 89 mm |
| 4x6 | 3.5 in | 5.5 in | 89 × 140 mm |
| 6x6 | 5.5 in | 5.5 in | 140 × 140 mm |
Nominal vs. Actual Lumber Size
Lumber is commonly sold using nominal dimensions such as 2x4, 2x6, or 4x4. These names describe the nominal size rather than the final finished dimensions.
After drying and surfacing, the actual dimensions are smaller than the nominal dimensions. For example, a commonly sold dry 2x4 measures approximately 1.5 × 3.5 inches.
Actual dimensions can vary depending on lumber type, moisture condition, manufacturing, grade, and product specifications.
Individual Lumber Size Pages
How to Read a Lumber Size
The first number generally describes the nominal thickness and the second number describes the nominal width. For example, 2x6 refers to lumber with a nominal thickness of 2 inches and nominal width of 6 inches.
The actual finished dimensions are normally smaller than the nominal dimensions. Always check the actual dimensions when precise measurements are important.