Lumber Weight Calculator — Wood, Plywood & Logs
Estimate board, sheet, and log weight from species density and moisture content.
Total Weight
14.7 lb
6.7 kg · Red Oak (Northern), kiln-dried, 44 lb/ft³
Per Piece
—
Volume
0.33 ft³
96 in × 6 in × 1 in
What determines lumber weight
Two things: species density and moisture content. Density varies enormously across species — kiln-dried western red cedar is about 23 lb/ft³ while shagbark hickory is 51 lb/ft³, more than double. Moisture matters just as much: freshly cut ("green") wood carries water equal to 30–100%+ of its oven-dry weight, which kiln drying brings down to roughly 6–12% moisture content.
The densities in this calculator are species averages derived from the USDA Forest Products Laboratory Wood Handbook (2021). Individual boards commonly vary ±10% either way, so treat results as close estimates rather than scale readings.
How the weight is calculated
Weight = volume × density, with volume from your dimensions:
- Boards and sheets: Volume (ft³) = (L × W × T) ÷ 1728, all inches
- Logs: Volume (ft³) = π × (D ÷ 24)² × L, diameter in inches, length in feet
The log formula treats the log as a cylinder at its mid-length diameter, which averages out the taper. Logs are weighed green by default — that's their state when you're actually moving them.
One useful shortcut that falls out of the math: weight per board foot = density ÷ 12. Kiln-dried red oak at 44 lb/ft³ is about 3.7 lb per board foot.
Wood weight chart by species
Approximate densities and per-board-foot weights. Kiln-dried is ~12% moisture content; green is freshly cut.
| Species | Kiln-dried (lb/ft³) | Green (lb/ft³) | lb per board foot (KD) |
|---|---|---|---|
| White Ash | 42 | 48 | 3.5 |
| Yellow Birch | 43 | 57 | 3.6 |
| Black Cherry | 35 | 45 | 2.9 |
| Hickory (Shagbark) | 51 | 64 | 4.3 |
| Hard Maple | 44 | 56 | 3.7 |
| Soft Maple (Red) | 38 | 50 | 3.2 |
| Red Oak (Northern) | 44 | 63 | 3.7 |
| White Oak | 47 | 62 | 3.9 |
| Yellow Poplar | 29 | 38 | 2.4 |
| Black Walnut | 38 | 58 | 3.2 |
| Western Red Cedar | 23 | 27 | 1.9 |
| Douglas Fir | 34 | 39 | 2.8 |
| Southern Yellow Pine | 36 | 53 | 3.0 |
| Eastern White Pine | 25 | 36 | 2.1 |
| Redwood | 28 | 50 | 2.3 |
| Spruce-Pine-Fir (SPF) | 28 | 34 | 2.3 |
Plywood and sheet goods weight
Full 4×8 sheet weights at common thicknesses. Sheet goods have no green/dry split — they're manufactured at a stable moisture content — but actual weight varies by manufacturer, and sanded "3/4-inch" panels are often 23/32" and slightly lighter.
| Material | Density (lb/ft³) | 1/2" 4×8 sheet | 3/4" 4×8 sheet |
|---|---|---|---|
| Softwood Plywood | 35 | 47 lb | 70 lb |
| Hardwood / Baltic Birch Plywood | 42 | 56 lb | 84 lb |
| OSB | 40 | 53 lb | 80 lb |
| MDF | 48 | 64 lb | 96 lb |
| Particleboard | 44 | 59 lb | 88 lb |
Estimating log weight
Log weight is what matters when you're deciding whether a trailer, tractor, or your back can handle it. Use the log mode with the diameter measured at mid-length, inside the bark. Logs should be weighed green: a 16-inch × 8-foot red oak log runs about 700 lb — green oak is around 63 lb/ft³, and none of that water has left yet.
Two caveats. The cylinder formula slightly overestimates strongly tapered logs, and bark (not included here) can add several percent. When rigging or loading, round up, not down.
Frequently asked questions
- How much does an 8-foot 2x4 weigh?
- A kiln-dried 8-foot 2x4 (actual 1.5" × 3.5" × 96") weighs about 8 lb in SPF and about 10.5 lb in southern yellow pine. Freshly treated or green lumber holds much more water — a wet pressure-treated 2x4 can exceed 15 lb. For fresh pressure-treated stock, use the green setting.
- How much does a 4x8 sheet of 3/4-inch plywood weigh?
- Approximately 70 lb for softwood plywood, 84 lb for hardwood or Baltic birch plywood, 80 lb for OSB, and 96 lb for MDF. Actual sheet weight varies by manufacturer and exact panel thickness — sanded "3/4-inch" panels are often 23/32" and weigh slightly less.
- Why does green wood weigh so much more than kiln-dried?
- Freshly cut wood carries water equal to 30–100%+ of its oven-dry weight, depending on species. Kiln drying brings lumber down to roughly 6–12% moisture content. That water is pure added weight: green red oak runs about 63 lb/ft³ versus 44 lb/ft³ kiln-dried.
- How much does a cord of firewood weigh?
- A full cord is 128 ft³ of stacked wood, roughly 85 ft³ of solid wood after air gaps. Green oak runs about 5,300 lb per cord; well-seasoned oak about 3,700 lb. Lighter species like pine run roughly 2,000–3,000 lb seasoned.
- How accurate are these weights?
- Solid-wood densities are species averages at 12% moisture content (kiln-dried) and green, based on USDA Forest Products Laboratory Wood Handbook data. Individual boards commonly vary ±10% with growth conditions and exact moisture content, and sheet goods vary by manufacturer. Treat results as close estimates, not scale readings.