Quick-reference for nominal vs. actual lumber dimensions and screw pilot-hole sizes for softwood and hardwood.
| Nominal size | Actual dimensions | Thickness (in) | Width (in) |
|---|---|---|---|
| 1×2 | 3/4" × 1-1/2" | 0.75 | 1.5 |
| 1×3 | 3/4" × 2-1/2" | 0.75 | 2.5 |
| 1×4 | 3/4" × 3-1/2" | 0.75 | 3.5 |
| 1×6 | 3/4" × 5-1/2" | 0.75 | 5.5 |
| 1×8 | 3/4" × 7-1/4" | 0.75 | 7.25 |
| 1×10 | 3/4" × 9-1/4" | 0.75 | 9.25 |
| 1×12 | 3/4" × 11-1/4" | 0.75 | 11.25 |
| 2×2 | 1-1/2" × 1-1/2" | 1.5 | 1.5 |
| 2×3 | 1-1/2" × 2-1/2" | 1.5 | 2.5 |
| 2×4 | 1-1/2" × 3-1/2" | 1.5 | 3.5 |
| 2×6 | 1-1/2" × 5-1/2" | 1.5 | 5.5 |
| 2×8 | 1-1/2" × 7-1/4" | 1.5 | 7.25 |
| 2×10 | 1-1/2" × 9-1/4" | 1.5 | 9.25 |
| 2×12 | 1-1/2" × 11-1/4" | 1.5 | 11.25 |
| 4×4 | 3-1/2" × 3-1/2" | 3.5 | 3.5 |
| 4×6 | 3-1/2" × 5-1/2" | 3.5 | 5.5 |
| 4×8 | 3-1/2" × 7-1/4" | 3.5 | 7.25 |
| 6×6 | 5-1/2" × 5-1/2" | 5.5 | 5.5 |
| 6×8 | 5-1/2" × 7-1/2" | 5.5 | 7.5 |
| 8×8 | 7-1/2" × 7-1/2" | 7.5 | 7.5 |
Dimensions are for kiln-dried, surfaced (S4S) lumber. Green or rough-sawn lumber will measure slightly larger. Tolerances of ±1/32" are common.
| Size | Outer Ø | Hardwood pilot | Softwood pilot | Clearance hole | Common use |
|---|---|---|---|---|---|
| #0 | 0.060" | 1/32" | 1/64" | 1/16" | Small hinges, jewelry boxes |
| #1 | 0.073" | 1/32" | 1/32" | 5/64" | Light hinges, small hardware |
| #2 | 0.086" | 3/64" | 1/32" | 3/32" | Small trim, electrical boxes |
| #3 | 0.099" | 1/16" | 3/64" | 7/64" | Hinges, light trim work |
| #4 | 0.112" | 1/16" | 3/64" | 1/8" | Cabinet hardware, light trim |
| #5 | 0.125" | 5/64" | 1/16" | 9/64" | Cabinet face frames, thin stock |
| #6 | 0.138" | 3/32" | 5/64" | 9/64" | General woodworking, 1× boards |
| #7 | 0.151" | 7/64" | 3/32" | 5/32" | Trim, decking, furniture |
| #8 | 0.164" | 7/64" | 3/32" | 11/64" | Most common — 2× framing, cabinets |
| #9 | 0.177" | 1/8" | 7/64" | 3/16" | Heavy trim, structural connections |
| #10 | 0.190" | 1/8" | 7/64" | 3/16" | Decking, structural, hardware |
| #12 | 0.216" | 9/64" | 1/8" | 7/32" | Heavy structural, ledger boards |
| #14 | 0.242" | 11/64" | 9/64" | 1/4" | Heavy-duty structural, decking |
Pilot hole sizes are guidelines — always test on scrap first. Hardwood requires a slightly larger pilot hole to prevent splitting. The clearance hole lets the screw shank pass freely for a tight draw-down joint.