1x12 actual size, board feet and weight calculator
Nominal lumber sizes describe the rough-sawn dimension before drying and planing. A 1x12 finishes at 0.75 by 11.25 inches, but board feet are still billed on the nominal size.
Douglas fir 530; southern yellow pine 640; spruce 450.
- Board feet per piece
- 8.000
- Total weight
- 70.35
- Weight per piece
- 7.035
- Total linear feet
- 80.0
- Total cost
- 95.00
- Cost per board foot
- 1.188
- Cross-sectional area
- 5444 mm2
Show the working
- Length of each piece = 8
- Number of pieces = 10
- Wood density = 530
- Price per piece = 9.5
- actual_t = 0.75 = 0.75
- actual_w = 11.25 = 11.25
- nominal_t = 1 = 1
- nominal_w = 12 = 12
- Board feet per piece = 1 * 12 * 8 / 12 = 8
- Board feet = 8 * 10 = 80
- actual_volume_m3 = 0.75 * 11.25 * 8 * 12 * 0.0254^3 = 0.013 273 5
- Weight per piece = 0.013 273 5 * 530 = 7.034 97
- Total weight = 7.034 97 * 10 = 70.3497
- Total linear feet = 8 * 10 = 80
- Total cost = 9.5 * 10 = 95
- Cost per board foot = 80 > 0 ? 95 / 80 : 0 = 1.1875
- Cross-sectional area = 0.75 * 11.25 * 645.16 = 5443.54
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- board feet = nominal thickness x nominal width x length in feet / 12
- weight = actual cross-section x length x density
Board feet use the nominal size, weight uses the actual size. Mixing them up overstates weight by about 25% on dimensional lumber.
Actual sizes are for dry, surfaced-four-sides softwood. Rough-sawn and green lumber run larger.
Wood weight varies with moisture content: freshly cut softwood can be half again as heavy as kiln-dried.
Nominal against actual
| Measure | Nominal | Actual (in) | Actual (mm) |
|---|---|---|---|
| Thickness | 1 in | 0.75 | 19.0 |
| Width | 12 in | 11.25 | 285.8 |
Frequently asked
What are the actual dimensions of a 1x12?
0.75 by 11.25 inches, or 19.0 by 285.8 mm, surfaced and dry.
Why is a 1x12 not actually 1 by 12 inches?
The nominal size is the green, rough-sawn dimension. Drying shrinks it and planing takes off the rest.