Lumber Size Chart: Nominal vs Actual (2x4 = ?) | TaskHolt
Lumber Size Chart (Nominal vs Actual)
The nominal vs actual size of dimensional lumber — what a 2×4 really measures — for boards and studs in inches.
Dimensional lumber: nominal vs actual
| Nominal | Actual (in) |
|---|---|
| 1 × 2 | 3/4 × 1-1/2 |
| 1 × 4 | 3/4 × 3-1/2 |
| 1 × 6 | 3/4 × 5-1/2 |
| 1 × 8 | 3/4 × 7-1/4 |
| 1 × 10 | 3/4 × 9-1/4 |
| 1 × 12 | 3/4 × 11-1/4 |
| 2 × 2 | 1-1/2 × 1-1/2 |
| 2 × 4 | 1-1/2 × 3-1/2 |
| 2 × 6 | 1-1/2 × 5-1/2 |
| 2 × 8 | 1-1/2 × 7-1/4 |
| 2 × 10 | 1-1/2 × 9-1/4 |
| 2 × 12 | 1-1/2 × 11-1/4 |
| 4 × 4 | 3-1/2 × 3-1/2 |
| 6 × 6 | 5-1/2 × 5-1/2 |
Boards are sold by nominal size, but the actual milled size is smaller because the wood is planed smooth and dried after rough-cutting. A “2×4” is really 1-1/2 × 3-1/2 in.
Frequently asked questions
Why is a 2x4 not actually 2x4 inches?
The nominal size is the rough-cut dimension. After drying and planing smooth, a 2×4 finishes at 1-1/2 × 3-1/2 in.
What is the actual size of a 1x6 board?
A nominal 1×6 board actually measures 3/4 in thick by 5-1/2 in wide.