Wood weight calculator: how much does a piece of lumber weigh?
9.77 lb
33.5 lb per cu ft at 12% moisture, specific gravity 0.48 · actual 1 1/2 × 3 1/2 in · for one 2x4, 8 ft
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9.77 lb
33.5 lb per cu ft at 12% moisture, specific gravity 0.48 · actual 1 1/2 × 3 1/2 in
Source: USDA Forest Service, Forest Products Laboratory, Wood Handbook: Wood as an Engineering Material (FPL-GTR-190), Tables 4-6b and 5-3b, read October 24, 2026. Data sheet (PDF)
A dry 8 ft 2x4 of Douglas-fir weighs 9.77 lb: 33.5 lb per cubic foot at 12% moisture (USDA Wood Handbook Table 4-6b, specific gravity 0.48 from Table 5-3b) times its actual 1 1/2 × 3 1/2 in section.
A worked example
14 green white oak 2x10s, 12 ft long, at 60% moisture needs 1,037.3 lb. Green white oak has a specific gravity of 0.60, which Table 4-6b puts at 59.9 lb per cu ft at 60% moisture. A green 2x10 dresses to 1 9/16 × 9 1/2 in under PS 20, so each 12 ft piece is 1.24 cu ft and 74.1 lb.
How much does a 2x4 weigh?
An 8 ft 2x4 weighs 9.77 lb in dry Douglas-fir, 10.4 lb in dry loblolly pine and 6.53 lb in western redcedar, from the Wood Handbook density at 12% moisture and the 1 1/2 × 3 1/2 in actual size. A 10 ft 2x4 of dry Douglas-fir is 12.2 lb.
How much heavier is green wood?
Much heavier, because of the water: Douglas-fir runs 33.5 lb per cu ft dry at 12% moisture and 44.9 lb at 60% with its green specific gravity of 0.45, by Wood Handbook Tables 4-6b and 5-3b.
What else it is called
Also searched as a lumber weight calculator, board weight calculator, wood beam weight or how much does a 2x4 weigh. Southern Pine lumber, the southern yellow pine of the lumber yard, comes from four species: longleaf, shortleaf, loblolly and slash pine, by the Wood Handbook.
Weight of an 8 ft board
| 8 ft piece | Douglas-fir | Loblolly pine | Western redcedar | Northern red oak | White oak |
|---|---|---|---|---|---|
| 1x6 | 7.68 lb | 8.16 lb | 5.13 lb | 10.1 lb | 10.9 lb |
| 2x4 | 9.77 lb | 10.4 lb | 6.53 lb | 12.8 lb | 13.9 lb |
| 2x6 | 15.4 lb | 16.3 lb | 10.3 lb | 20.2 lb | 21.8 lb |
| 2x8 | 20.2 lb | 21.5 lb | 13.5 lb | 26.6 lb | 28.7 lb |
| 2x10 | 25.8 lb | 27.4 lb | 17.3 lb | 33.9 lb | 36.6 lb |
| 2x12 | 31.4 lb | 33.4 lb | 21 lb | 41.3 lb | 44.5 lb |
| 4x4 | 22.8 lb | 24.2 lb | 15.2 lb | 29.9 lb | 32.3 lb |
| 4x6 | 35.8 lb | 38.1 lb | 24 lb | 47.1 lb | 50.8 lb |
Dry, 12% moisture: the Wood Handbook (FPL-GTR-190) Table 4-6b density for the 12% specific gravity of each species in Table 5-3b, times the PS 20 dry dressed size (a 2x4 is 1 1/2 × 3 1/2 in).
Where the numbers come from
- Density: USDA Wood Handbook (FPL-GTR-190), Table 4-6b «Density of wood as a function of specific gravity and moisture content», in lb per cubic foot with the water included, interpolated between specific gravity columns as the Handbook does. Specific gravity by species, green and at 12% moisture: Table 5-3b. Above about 30% moisture the specific gravity stops changing, so green wood uses the green figure. Read October 24, 2026. Wood Handbook (PDF)
- Actual sizes: PS 20-20 American Softwood Lumber Standard, Table 3, dry and green dressed sizes (a 2x4 is 1 1/2 × 3 1/2 in dry). Read October 2, 2026. PS 20 (PDF)
- The rest is arithmetic: pounds = lb per cu ft × actual thickness × actual width ÷ 144 × length ft × pieces.
Figures are averages for clear wood of each species; a knotty or resin-soaked board can weigh more. The Wood Handbook gives no figure for pressure-treated lumber, so it is not one of the choices.
By Javier Miralles · Last updated . How this site is made.
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