Lumber Weight Calculator
Calculate the weight of lumber by species, size, and moisture content
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Quick Answer
A standard 8-foot 2×4 of kiln-dried Southern Yellow Pine weighs about 13 pounds. Weight varies significantly by species—oak can weigh nearly twice as much as cedar. Green (wet) lumber weighs up to 50% more than kiln-dried.
Dr. Snezana Lawrence
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How to Calculate Lumber Weight
Calculating lumber weight requires knowing the wood species (which determines density), the actual dimensions, and the moisture content. The formula is straightforward once you have these values.
Lumber Weight Formula
Volume (cu ft) = (Width × Height × Length) ÷ 1728Weight (lb) = Volume × Density × Moisture MultiplierWhere dimensions are in inches and density is in lb/ft³
Worked Example
Lumber: 2×4×8 Southern Yellow Pine (kiln-dried)
Actual dimensions: 1.5" × 3.5" × 96"
Volume = (1.5 × 3.5 × 96) ÷ 1728 = 0.292 cu ft
Weight = 0.292 × 35 × 1.0 = 10.2 lb
Result: ~10 pounds per 2×4×8
Wood Density by Species
Wood density varies dramatically between species. Softwoods generally weigh less than hardwoods, but there are exceptions. These values are at 12% moisture content (standard kiln-dried).
| Species | Density (lb/ft³) | Category |
|---|---|---|
| Western Red Cedar | 23 | Softwood (Lightest) |
| White Pine | 25 | Softwood |
| Spruce | 27 | Softwood |
| Douglas Fir | 32 | Softwood |
| Southern Yellow Pine | 35 | Softwood |
| Poplar | 29 | Hardwood (Light) |
| Cherry | 35 | Hardwood |
| Ash | 41 | Hardwood |
| Red Oak | 44 | Hardwood |
| White Oak | 47 | Hardwood |
| Hickory | 50 | Hardwood (Heavy) |
| Ipe | 69 | Exotic (Heaviest) |
Common Lumber Weights
Here are typical weights for common lumber sizes using SPF (Spruce-Pine-Fir) and Southern Yellow Pine, the most common framing lumber types.
| Size | SPF (lb) | SYP (lb) | Per Foot |
|---|---|---|---|
| 2×4×8 | 9 | 13 | 1.1-1.6 |
| 2×4×10 | 11 | 16 | 1.1-1.6 |
| 2×4×12 | 13 | 19 | 1.1-1.6 |
| 2×6×8 | 14 | 20 | 1.8-2.5 |
| 2×6×10 | 18 | 25 | 1.8-2.5 |
| 2×6×12 | 21 | 30 | 1.8-2.5 |
| 2×8×8 | 19 | 27 | 2.4-3.4 |
| 2×10×8 | 24 | 34 | 3.0-4.3 |
| 2×12×8 | 29 | 42 | 3.6-5.2 |
| 4×4×8 | 21 | 30 | 2.6-3.7 |
SPF = Spruce-Pine-Fir, SYP = Southern Yellow Pine. Weights are approximate for kiln-dried lumber.
Moisture Content and Weight
Wood is hygroscopic, meaning it absorbs and releases moisture from the environment. The moisture content significantly affects weight—freshly cut "green" lumber can contain more water than wood fiber by weight.
Kiln Dried
8-12%
Standard lumber from stores. Stable, ready for construction. Base weight reference.
Air Dried
15-20%
Naturally seasoned. ~15% heavier than kiln-dried. May need further drying for interior use.
Green
30-200%
Freshly cut. Up to 50%+ heavier. Will shrink and warp as it dries.
Why It Matters
Green lumber is significantly heavier, affecting transportation costs and handling. A truck that can carry 40,000 lbs of kiln-dried lumber might only safely carry 28,000 lbs of green lumber.
Nominal vs Actual Dimensions
Lumber is sold by nominal (name) dimensions, but the actual dimensions are smaller due to drying and planing. Always use actual dimensions for weight calculations.
| Nominal | Actual | Cross-Section (sq in) |
|---|---|---|
| 1×4 | 3/4" × 3-1/2" | 2.63 |
| 1×6 | 3/4" × 5-1/2" | 4.13 |
| 2×4 | 1-1/2" × 3-1/2" | 5.25 |
| 2×6 | 1-1/2" × 5-1/2" | 8.25 |
| 2×8 | 1-1/2" × 7-1/4" | 10.88 |
| 2×10 | 1-1/2" × 9-1/4" | 13.88 |
| 2×12 | 1-1/2" × 11-1/4" | 16.88 |
| 4×4 | 3-1/2" × 3-1/2" | 12.25 |
| 6×6 | 5-1/2" × 5-1/2" | 30.25 |
Frequently Asked Questions
How much does a 2×4 weigh?
An 8-foot kiln-dried 2×4 weighs 9-13 pounds depending on species. SPF (spruce-pine-fir) weighs about 9-11 lbs, while denser Southern Yellow Pine weighs about 13 lbs. Douglas Fir falls in between at about 11-12 lbs. Green lumber can weigh 50% more.
How do you calculate lumber weight?
Calculate lumber weight using the formula: Weight = Volume × Density. First find volume in cubic feet by multiplying Width × Height × Length in inches and dividing by 1728. Then multiply by the wood density in pounds per cubic foot (varies by species from 22-69 lb/ft³).
What is the heaviest common lumber?
Among common domestic lumber, hickory is the heaviest at about 50 lb/ft³. White oak (47 lb/ft³) and hard maple (44 lb/ft³) are also very dense. For exotic woods, ipe (Brazilian walnut) is extremely heavy at 69 lb/ft³—nearly 3 times heavier than cedar.
Why does moisture content affect lumber weight?
Wood absorbs and holds water in its cell walls and cavities. Green (freshly cut) wood contains 30-200% moisture content by weight. As wood dries, it loses this water weight. Kiln-dried lumber (8-12% moisture) weighs 35-50% less than the same green lumber.
How much does pressure treated lumber weigh?
Pressure treated lumber weighs more than untreated lumber due to the preservative chemicals forced into the wood. A pressure-treated 2×4×8 typically weighs 15-20 lbs compared to 9-13 lbs for untreated. The wood is also often sold with higher moisture content.
What is the lightest construction lumber?
Western Red Cedar is the lightest common construction lumber at about 23 lb/ft³. White Cedar (22 lb/ft³) is similar. For comparison, these are about half the weight of oak. Cedar is popular for outdoor projects where lifting and handling matter.
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Dr. Snezana Lawrence
Mathematical Historian | PhD from Yale
Dr. Lawrence is a published mathematical historian with a PhD from Yale University. She ensures mathematical precision and accuracy in all our calculations, conversions, and academic score calculators. Her expertise spans computational mathematics and educational assessment.
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