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Lumber Weight Calculator

How much a board, a stack of studs or a load of hardwood weighs, from its size, the species and how wet the wood is, using the USDA Wood Handbook.

Built by AbhiLast reviewed September 25, 2026

LengthThickness,actualWidth, actual

The real size, not the name: a 2×4 is 1 1/2 × 3 1/2 in once dried and planed.

Water as a share of the dry wood’s weight. Read it with a moisture meter, or from the grade stamp.

Result

Buy 9.9 lbEstimate

An average for clear wood of the species. Real boards vary by about a tenth either way.

Weight of one piece
9.9 lb (4.5 kg)Estimate
Density at this moisture
33.9 lb/ft³ (542.8 kg/m³)Estimate
Specific gravity at this moisture
0.485Estimate
Wood volume, actual size
3.5 bd ft (0.292 ft³)
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Results are estimates for planning only. Actual needs vary with site conditions, products and workmanship. Always confirm quantities with your supplier and follow local building codes and manufacturer instructions. Read the full disclaimer

How to use the Lumber Weight Calculator

  1. Enter the actual thickness and width of the board, its length and how many pieces there are.
  2. Pick the species, or choose Other and enter its basic specific gravity.
  3. Enter the moisture content, from a moisture meter or the grade stamp.
  4. Read the total weight, the weight of one piece and the density of the wood at that moisture.

How it is calculated

Gₓ      = G_b ÷ (1 − 0.265 × G_b × (1 − x ÷ 30%))     below 30% moisture        = G_b                                          at 30% and abovedensity = 1,000 kg/m³ × Gₓ × (1 + x)weight  = density × thickness × width × length × pieces

G_b is the basic specific gravity, x the moisture content as a share of dry weight. These are equations 4-13 and 4-14 in chapter 4 of the USDA Forest Products Laboratory’s Wood Handbook (2021). The 0.265 comes from Stamm’s estimate that wood shrinks in volume from green to oven-dry by about 26.5 percent times its basic specific gravity, so 11.9% for a wood of 0.45; the 30% is the handbook’s fibre saturation point.

The species values

Each species uses the average basic specific gravity in the handbook’s Table 5-3a: coast Douglas-fir 0.45, loblolly pine 0.47, eastern white pine 0.34, western redcedar 0.31, northern red oak 0.56, white oak 0.60, sugar maple 0.56, black walnut 0.51 and white ash 0.55. Southern pine is sold as a group of species, of which loblolly is one; longleaf, at 0.54, is denser. For any other wood, look up its green specific gravity in the same table and choose Other.

Nominal and actual sizes

Softwood lumber is named by a nominal size and sold smaller: a 2×4 is 1 1/2 by 3 1/2 inches and a 2×10 is 1 1/2 by 9 1/4 inches once dried and planed. Enter the size you would measure with a tape.

A check against the handbook

The handbook’s own worked example is white ash at 12% moisture, which it reads off a chart as a specific gravity of 0.605 and a density of 678 kg/m³. The equation gives 0.603 and 675 kg/m³, the difference being how finely the chart can be read.

With your numbers

  1. Specific gravity at 12% = 0.485
  2. Density = water × 0.485 × (1 + 12%) = 33.89 lb/ft³
  3. Weight = density × volume = 9.884 lb

Quick reference

An average for clear wood of the species. Real boards vary by about a tenth either way.

Common jobs, worked out with the options this calculator starts on for United States.
JobTotal weight
2×4 × 8 ft Douglas-fir, 12%9.9 lb
50 2×4 × 8 ft, 19%509.8 lb
2×10 × 12 ft southern pine, 15%41.6 lb
1×6 × 8 ft white oak, 8%10.5 lb
4×4 × 8 ft cedar, green21.1 lb
38 × 89 mm × 2.4 m pine, 15%4.7 kg
25 × 150 mm × 2 m walnut, 8%4.6 kg

Where the numbers come from

The fixed figures this calculator relies on, and the published source each one was checked against. How the calculators are built and checked

10 sources

  1. NIST Chemistry WebBook, water at 4 °C and 0.101325 MPa: 999.9749 kg/m³ (IAPWS-95), https://webbook.nist.gov/cgi/fluid.cgi?ID=C7732185, rounded to the conventional 1000 kg/m³ of NIST SP 811 (2008) Appendix B, centimeter of water, conventional = 98.0665 Pa.

    Used for

    • The conventional density of water, 1000 kg/m³. Pure water at 4 °C, its densest, is 999.97 kg/m³.

  2. Senalik, C.A.; Farber, B. 2021. Chapter 5: Mechanical properties of wood. In: Wood handbook, FPL-GTR-282, USDA Forest Products Laboratory, Table 5-3a, "Douglas-fir, Coast", Green row, specific gravity 0.45; footnote b: "Specific gravity is based on weight when ovendry and volume when green or at 12% moisture content." https://research.fs.usda.gov/treesearch/62244

    Used for

    • Basic specific gravity of Douglas-fir, Coast: ovendry weight over green volume, the species average for clear wood.

  3. Senalik, C.A.; Farber, B. 2021. Chapter 5: Mechanical properties of wood. In: Wood handbook, FPL-GTR-282, USDA Forest Products Laboratory, Table 5-3a, "Pine, Loblolly", Green row, specific gravity 0.47; footnote b: "Specific gravity is based on weight when ovendry and volume when green or at 12% moisture content." https://research.fs.usda.gov/treesearch/62244

    Used for

    • Basic specific gravity of Pine, Loblolly: ovendry weight over green volume, the species average for clear wood.

  4. Senalik, C.A.; Farber, B. 2021. Chapter 5: Mechanical properties of wood. In: Wood handbook, FPL-GTR-282, USDA Forest Products Laboratory, Table 5-3a, "Pine, Eastern white", Green row, specific gravity 0.34; footnote b: "Specific gravity is based on weight when ovendry and volume when green or at 12% moisture content." https://research.fs.usda.gov/treesearch/62244

    Used for

    • Basic specific gravity of Pine, Eastern white: ovendry weight over green volume, the species average for clear wood.

  5. Senalik, C.A.; Farber, B. 2021. Chapter 5: Mechanical properties of wood. In: Wood handbook, FPL-GTR-282, USDA Forest Products Laboratory, Table 5-3a, "Western redcedar", Green row, specific gravity 0.31; footnote b: "Specific gravity is based on weight when ovendry and volume when green or at 12% moisture content." https://research.fs.usda.gov/treesearch/62244

    Used for

    • Basic specific gravity of Western redcedar: ovendry weight over green volume, the species average for clear wood.

  6. Senalik, C.A.; Farber, B. 2021. Chapter 5: Mechanical properties of wood. In: Wood handbook, FPL-GTR-282, USDA Forest Products Laboratory, Table 5-3a, "Oak, red, Northern red", Green row, specific gravity 0.56; footnote b: "Specific gravity is based on weight when ovendry and volume when green or at 12% moisture content." https://research.fs.usda.gov/treesearch/62244

    Used for

    • Basic specific gravity of Oak, red, Northern red: ovendry weight over green volume, the species average for clear wood.

  7. Senalik, C.A.; Farber, B. 2021. Chapter 5: Mechanical properties of wood. In: Wood handbook, FPL-GTR-282, USDA Forest Products Laboratory, Table 5-3a, "Oak, white, White", Green row, specific gravity 0.6; footnote b: "Specific gravity is based on weight when ovendry and volume when green or at 12% moisture content." https://research.fs.usda.gov/treesearch/62244

    Used for

    • Basic specific gravity of Oak, white, White: ovendry weight over green volume, the species average for clear wood.

  8. Senalik, C.A.; Farber, B. 2021. Chapter 5: Mechanical properties of wood. In: Wood handbook, FPL-GTR-282, USDA Forest Products Laboratory, Table 5-3a, "Maple, Sugar", Green row, specific gravity 0.56; footnote b: "Specific gravity is based on weight when ovendry and volume when green or at 12% moisture content." https://research.fs.usda.gov/treesearch/62244

    Used for

    • Basic specific gravity of Maple, Sugar: ovendry weight over green volume, the species average for clear wood.

  9. Senalik, C.A.; Farber, B. 2021. Chapter 5: Mechanical properties of wood. In: Wood handbook, FPL-GTR-282, USDA Forest Products Laboratory, Table 5-3a, "Walnut, black", Green row, specific gravity 0.51; footnote b: "Specific gravity is based on weight when ovendry and volume when green or at 12% moisture content." https://research.fs.usda.gov/treesearch/62244

    Used for

    • Basic specific gravity of Walnut, black: ovendry weight over green volume, the species average for clear wood.

  10. Senalik, C.A.; Farber, B. 2021. Chapter 5: Mechanical properties of wood. In: Wood handbook, FPL-GTR-282, USDA Forest Products Laboratory, Table 5-3a, "Ash, White", Green row, specific gravity 0.55; footnote b: "Specific gravity is based on weight when ovendry and volume when green or at 12% moisture content." https://research.fs.usda.gov/treesearch/62244

    Used for

    • Basic specific gravity of Ash, White: ovendry weight over green volume, the species average for clear wood.

Common questions about the Lumber Weight Calculator

How much does a 2×4 weigh?
A kiln-dried coast Douglas-fir 2×4, actually 1 1/2 by 3 1/2 inches and 8 feet long, weighs about 10 pounds at 12% moisture by the Wood Handbook method. The same stud green, at 60% moisture, is about 13 pounds: much of the weight of fresh lumber is water.
Why does wetter wood weigh more but not in proportion?
Two things change. The water adds weight directly, but wood also swells as it takes up water, up to its fibre saturation point of about 30%, so each cubic foot holds a little less wood. Above about 30% the wood stops swelling and every extra percent is just water.
What is basic specific gravity?
The weight of the wood when oven-dry, divided by the weight of water that fills the same volume as the wood when green. It is how the Wood Handbook tabulates species, and it is the starting point for the density at any other moisture.
How accurate is this?
It is a species average for clear wood. The handbook puts the variation within a species at about 10%, and knots, resin, heartwood and growth rate all move it. Treated lumber is heavier again, by an amount that depends on the treatment and is not in the handbook.

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