Quick Answer
2×8 Actual Size: 1.5 in × 7.25 in (38 mm × 184 mm)
The real, finished size of a standard “2×8” is 1.5 inches by 7.25 inches, which is 38 mm by 184 mm.
“2×8” is the nominal name; after drying and planing, the board finishes smaller.
Quick dimensions
| Label | Inches | Millimeters |
|---|---|---|
| 2×8 actual size | 1.5″ × 7.25″ | 38 × 184 |
| 2×8 width | 7.25″ | 184 |
| 2×8 thickness | 1.5″ | 38 |
Also searched as: 2×8 dimensions, 2×8 actual measurement, 2×8 true size, 2×8 size in mm.
Nominal vs actual (why sizes are smaller)
“2×8” is the rough-cut (nominal) size. After the board is dried and planed smooth, its finished, usable size becomes 1½″ × 7¼″. This is standard for North American softwood framing lumber.
Compare to other common sizes
| Nominal | Actual (in) | Actual (mm) |
|---|---|---|
| 2×4 | 1.5 × 3.5 | 38 × 89 |
| 2×6 | 1.5 × 5.5 | 38 × 140 |
| 2×8 | 1.5 × 7.25 | 38 × 184 |
| 2×10 | 1.5 × 9.25 | 38 × 235 |
| 4×4 | 3.5 × 3.5 | 89 × 89 |
FAQ: 2×8 actual size
What is the actual size of a 2×8?
It’s 1.5 inches by 7.25 inches (38 mm × 184 mm).
How wide is a 2×8?
7.25 inches (184 mm) wide; thickness is 1.5 inches (38 mm).
Do treated 2×8s measure the same?
Yes, pressure-treated 2×8s typically finish at the same dimensions; minor variation can occur due to moisture/milling.