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Wood Weight Calculator: Board and Lumber Weight by Species
This wood weight calculator estimates what a board, beam or stack of lumber weighs from its species, size and moisture content. It multiplies the piece’s volume by a density taken from the USDA Wood Handbook, so a 2×6 can be weighed on paper before it is lifted, loaded on a truck or hung on a wall. Nominal and actual lumber sizes, feet or metres, and a moisture setting are built in, and every formula and source is shown below.
How is this calculated?
Press Calculate to see the math with your numbers.
How the wood weight calculator works
The calculator multiplies the volume of the piece by the density of the wood. Three steps run in order:
- Volume (cubic feet) = thickness (in.) × width (in.) × length (ft) ÷ 144. Lumber is measured at its actual dressed size, not the nominal name, so a 2×6 is 1-1/2 by 5-1/2 inches.
- Density (lb per cubic foot) = 62.43 × G12 × (1 + MC ÷ 100). Here 62.43 lb/ft³ is the density of water, G12 is the specific gravity of the species (oven-dry weight over volume at 12% moisture), and MC is the moisture content in percent.
- Weight = volume × density. Kilograms are pounds × 0.45359237.
Both the water density and the density-from-specific-gravity relation come from Chapter 4 of the USDA Wood Handbook (FPL-GTR-190), and the species values are the 12% moisture column of Table 5-3b in Chapter 5. At 12% moisture the formula reproduces the Handbook’s own Table 4-6b to within its rounding step of 0.1 lb/ft³.
Moisture content
Water adds weight. For a moisture content other than 12%, the calculator keeps the piece the same size and scales the mass by (1 + MC ÷ 100). Wood also swells and shrinks below roughly 30% moisture, so the estimate is least exact far from 12%. The Handbook defines dry softwood lumber under 5 inches thick as lumber at 19% moisture or less (Chapter 6), which makes 19 a realistic setting for lumber bought as kiln-dried framing. Green lumber, above 19%, weighs more still.
Actual lumber sizes used
The size lists use the American Standard minimum dressed sizes for dry lumber from Wood Handbook Table 6-6.
| Nominal | Actual thickness or width (in.) |
|---|---|
| 1 | 3/4 |
| 2 | 1-1/2 |
| 3 | 2-1/2 |
| 4 | 3-1/2 |
| 5 | 4-1/2 |
| 6 | 5-1/2 |
| 8 | 7-1/4 |
| 10 | 9-1/4 |
| 12 | 11-1/4 |
Species values
| Species | G12 (Table 5-3b) | Density at 12% (lb/ft³) | Density at 12% (kg/m³) |
|---|---|---|---|
| Western redcedar | 0.32 | 22.4 | 358 |
| Eastern white pine | 0.35 | 24.5 | 392 |
| American basswood | 0.37 | 25.9 | 414 |
| Sitka spruce, ponderosa pine, old-growth redwood | 0.40 | 28.0 | 448 |
| Yellow-poplar | 0.42 | 29.4 | 470 |
| Western hemlock | 0.45 | 31.5 | 504 |
| Douglas-fir, coast | 0.48 | 33.6 | 538 |
| Black cherry | 0.50 | 35.0 | 560 |
| Southern pine, loblolly and shortleaf | 0.51 | 35.7 | 571 |
| Black walnut | 0.55 | 38.5 | 616 |
| Southern pine, longleaf and slash | 0.59 | 41.3 | 661 |
| White ash | 0.60 | 42.0 | 672 |
| Yellow birch | 0.62 | 43.4 | 694 |
| Sugar (hard) maple, northern red oak | 0.63 | 44.1 | 706 |
| American beech | 0.64 | 44.7 | 717 |
| White oak | 0.68 | 47.5 | 762 |
| Shagbark hickory | 0.72 | 50.3 | 806 |
The Handbook lists many more species. For one that is not in the list, pick the nearest specific gravity and treat the result as an estimate.
Worked example: an 8-foot 2×4
An 8-foot 2×4 of coast Douglas-fir at 12% moisture has G12 = 0.48.
- Volume = 1.5 × 3.5 × 8 ÷ 144 = 0.2917 ft³
- Density = 62.43 × 0.48 × 1.12 = 33.56 lb/ft³
- Weight = 0.2917 × 33.56 = 9.8 lb (4.4 kg)
Setting the moisture to 19%, the upper limit for dry lumber, raises the density to 35.66 lb/ft³ and the same stud to 10.4 lb. A 10-foot 2×6 of loblolly or shortleaf pine at 12% (G12 = 0.51) comes to 20.4 lb, or 2.04 lb per foot of length.
What the estimate leaves out
The density is a species average. Knots, resin, fast or slow growth, pressure treatment, paint and wet storage all move the real weight of a board, and a single board can differ from the average by a noticeable margin. Treat the result as a planning number for load, shipping and lifting, and weigh the piece when the exact figure matters.
Related tools
To check how much load a board can carry once it is in place, use the wood load capacity calculator. For a 2×6 specifically, the 2×6 weight calculator covers lumber and LVL weights, and the linear foot lumber calculator converts between linear feet and board feet. Beam sag is covered by the 2×6 deflection calculator.
Frequently asked questions
How much does a 2×4 weigh?
An 8-foot 2×4 of Douglas-fir at 12% moisture weighs about 9.8 lb, and about 10.4 lb at 19% moisture. Lighter species such as eastern white pine weigh less and dense species such as white oak weigh more. Pick the species and length in the calculator for a figure that matches the board.
How do you calculate the weight of wood from its density?
Find the volume in cubic feet (thickness in inches times width in inches times length in feet, divided by 144) and multiply it by the density in pounds per cubic foot. The density comes from the species specific gravity times 62.43 times one plus the moisture content as a fraction.
Why does moisture change the weight of lumber?
Wood holds water in its cell walls, and that water adds mass. Dry lumber is defined as 19% moisture or less, so the same board can weigh noticeably more when it is green. The calculator scales the mass by one plus the moisture fraction so the effect shows in the result.