Common Lumber Dimensions
Nominal vs. Actual Lumber Dimensions
Lumber sizes are usually given in “nominal” measurements. The nominal measurements are a board’s size before it has been planed smooth (surfaced) on all 4 sides. The actual measurements are the final size. Actual sizes may vary slightly due to the moisture content.
| Nominal Size | Actual Size | Nominal Size | Actual Size | Nominal Size | Actual Size |
| 1×2 | 3/4″ x 1-1/2″ | 2×2 | 1-1/2″ x 1-1/2″ | 4×4 | 3-1/2″ x 3-1/2″ |
| 1×3 | 3/4″ x 2-1/2″ | 2×3 | 1-1/2″ x 2-1/2″ | 4×6 | 3-1/2″ x 5-1/2″ |
| 1×4 | 3/4″ x 3-1/2″ | 2×4 | 1-1/2″ x 3-1/2″ | 6×6 | 5-1/2″ x 5-1/2″ |
| 1×5 | 3/4″ x 4-1/2″ | 2×6 | 1-1/2″ x 5-1/2″ | 5/4×6 | 1″ x 5-1/2″ |
| 1×6 | 3/4″ x 5-1/2″ | 2×8 | 1-1/2″ x 7-1/4″ | 8×8 | 7-1/4″ x 7-1/4″ |
| 1×8 | 3/4″ x 7-1/4″ | 2×10 | 1-1/2″ x 9-1/4″ | ||
| 1×10 | 3/4″ x 9-1/4″ | 2×12 | 1-1/2″ x 11-1/4″ | ||
| 1×12 | 3/4″ x 11-1/4″ |