Actual sizes of 1x boards
| Nominal | Actual size | Actual size (mm) | End area (actual) | Board feet per linear foot |
|---|---|---|---|---|
| 1x2 | 3/4" x 1-1/2" | 19 x 38 mm | 1.12 sq in | 0.167 |
| 1x3 | 3/4" x 2-1/2" | 19 x 64 mm | 1.88 sq in | 0.25 |
| 1x4 | 3/4" x 3-1/2" | 19 x 89 mm | 2.62 sq in | 0.333 |
| 1x6 | 3/4" x 5-1/2" | 19 x 140 mm | 4.12 sq in | 0.5 |
| 1x8 | 3/4" x 7-1/4" | 19 x 184 mm | 5.44 sq in | 0.667 |
| 1x10 | 3/4" x 9-1/4" | 19 x 235 mm | 6.94 sq in | 0.833 |
| 1x12 | 3/4" x 11-1/4" | 19 x 286 mm | 8.44 sq in | 1 |
A board sold as 1x is dried and planed down to 3/4 inch thick. The width follows the 1/2 inch rule up to 6 inches wide and the 3/4 inch rule at 8 inches and wider, under the American Softwood Lumber Standard (PS 20).
Board feet by length
Board feet go by the nominal size, so a 1x6 that is 8 ft long is 1 × 6 × 8 ÷ 12 = 4 board feet.
| Length | 1x4 | 1x6 | 1x8 | 1x10 | 1x12 |
|---|---|---|---|---|---|
| 6 ft | 2.00 | 3.00 | 4.00 | 5.00 | 6.00 |
| 8 ft | 2.67 | 4.00 | 5.33 | 6.67 | 8.00 |
| 10 ft | 3.33 | 5.00 | 6.67 | 8.33 | 10.00 |
| 12 ft | 4.00 | 6.00 | 8.00 | 10.00 | 12.00 |
| 16 ft | 5.33 | 8.00 | 10.67 | 13.33 | 16.00 |
Uses
- 1x2 and 1x3: furring strips, trim and small frames.
- 1x4 and 1x6: trim, shelving edges, fence pickets and boards for small projects.
- 1x8 to 1x12: shelves, siding, boxes and cabinets.
Not the same as 5/4
5/4 boards, the ones you often see as decking, land at about 1 inch thick after planing. That 5/4 name comes from the quarter system used for rough hardwood: 4/4 is 1 inch, 5/4 is 1-1/4 inches and 8/4 is 2 inches before surfacing. See how to calculate board feet for how the quarters are counted.
For 2x boards see the 2x6 and 2x8, 2x10 and 2x12 pages, or the full lumber dimensions chart.
Frequently asked questions
What is the actual size of a 1x4?
3/4 by 3-1/2 inches, or about 19 by 89 mm.
What is the actual size of a 1x6?
3/4 by 5-1/2 inches, or about 19 by 140 mm.
What is the actual size of a 1x12?
3/4 by 11-1/4 inches, or about 19 by 286 mm.
How many board feet are in a 1x6x8?
4 board feet: 1 x 6 x 8 divided by 12.
Why is a 1x board 3/4 inch thick?
A 1 inch rough board is dried and planed, which takes it down to 3/4 inch.