Lumber Sizes & Dimensions
Find actual dimensions for common U.S. lumber sizes, including nominal sizes, thickness, width, and metric dimensions.
Common Lumber Sizes
The table below provides reference dimensions for commonly used U.S. softwood lumber sizes.
| Nominal Size | Actual Thickness | Actual Width | Metric |
|---|---|---|---|
| 2×2 | 1.5 in | 1.5 in | 38 × 38 mm |
| 2×3 | 1.5 in | 2.5 in | 38 × 64 mm |
| 2×4 | 1.5 in | 3.5 in | 38 × 89 mm |
| 2×6 | 1.5 in | 5.5 in | 38 × 140 mm |
| 2×8 | 1.5 in | 7.25 in | 38 × 184 mm |
| 2×10 | 1.5 in | 9.25 in | 38 × 235 mm |
| 2×12 | 1.5 in | 11.25 in | 38 × 286 mm |
| 4×4 | 3.5 in | 3.5 in | 89 × 89 mm |
| 4×6 | 3.5 in | 5.5 in | 89 × 140 mm |
| 6×6 | 5.5 in | 5.5 in | 140 × 140 mm |
Dimensions are provided as general reference values. Actual dimensions can vary depending on product, species, moisture content, manufacturing, and applicable standards.
Nominal vs. Actual Lumber Size
Lumber is commonly identified by nominal dimensions such as 2×4, 2×6, or 4×4. These nominal dimensions are not the same as the finished actual dimensions of the lumber.
For example, a commonly sold 2×4 has an actual finished dimension of approximately 1.5 inches by 3.5 inches.
Learn more about why nominal lumber sizes differ from actual dimensions on our Nominal vs. Actual Lumber reference page.
Popular Lumber Sizes
Lumber Reference Guides
Lumber Size Chart — Browse common nominal and actual lumber dimensions.
Lumber Dimensions — Reference common thickness and width measurements.
Lumber Sizes in MM — Find common lumber dimensions in millimeters.
Frequently Asked Questions
What is the actual size of a 2×4?
A commonly sold dry 2×4 has an actual finished size of approximately 1.5 inches by 3.5 inches.
Why is a 2×4 not actually 2×4 inches?
Nominal lumber dimensions refer to the traditional size designation rather than the final dressed dimensions.
What is a 2×4 in millimeters?
A common 2×4 actual dimension is approximately 38 × 89 mm.
See all questions on the Lumber Reference FAQ.