Lumber Sizes
2024-02-22
Understanding nominal vs actual lumber dimensions: why a 2x4 isn't really 2 inches by 4 inches and what the real measurements are.
Source: Advantagelumber
Wood is often talked about in dimension terms like 2x4 but are those the real sizes? Of course not, that would be too easy .... The Nominal Sizes are the size when it's cut, but after drying and processing the sizes vary. Approximately the sizes below
| Nominal Size | Actual Size (Imperial) | Actual Size (Metric) |
|---|---|---|
| 1x4 | 0.75″ x 3.50″ | 19mm x 90mm |
| 1x5 | 0.75″ x 4.72″ | 19mm x 120mm |
| 1x6 | 0.75″ x 5.50″ | 19mm x 140mm |
| 1x4 +Plus® | 0.83″ x 3.50″ | 21mm x 90mm |
| 1x5 +Plus® | 0.83″ x 4.72″ | 21mm x 120mm |
| 1x6 +Plus® | 0.83″ x 5.50″ | 21mm x 140mm |
| 1x6 +Plus® XW™ | 0.83″ x 5.70″ | 21mm x 145mm |
| 5/4x4 | 1.00″ x 3.50″ | 25mm x 90mm |
| 5/4x5 | 1.00″ x 4.72″ | 25mm x 120mm |
| 5/4x6 | 1.00″ x 5.50″ | 25mm x 140mm |
| 5/4x8 | 1.00″ x 7.25″ | 25mm x 184mm |
| 5/4x10 | 1.00″ x 9.25″ | 25mm x 235mm |
| 5/4x12 | 1.00″ x 11.25″ | 25mm x 286mm |
| 2x2 | 1.50″ x 1.50″ | 38mm x 38mm |
| 2x4 | 1.50″ x 3.50″ | 38mm x 90mm |
| 2x6 | 1.50″ x 5.50″ | 38mm x 140mm |
| 2x8 | 1.50″ x 7.25″ | 38mm x 184mm |
| 2x10 | 1.50″ x 9.25″ | 38mm x 235mm |
| 2x12 | 1.50″ x 11.25″ | 38mm x 286mm |
| 3x4 | 2.50″ x 3.50″ | 64mm x 90mm |
| 3x6 | 2.50″ x 5.50″ | 64mm x 140mm |
| 3x8 | 2.50″ x 7.25″ | 64mm x 184mm |
| 3x10 | 2.50″ x 9.25″ | 64mm x 235mm |
| 3x12 | 2.50″ x 11.25″ | 64mm x 286mm |
| 4x4 | 3.50″ x 3.50″ | 90mm x 90mm |
| 6x6 | 5.50″ x 5.50″ | 140mm x 140mm |
