Calculate green and seasoned round timber weight, cubic volume, and sawmill board-foot yields using Huber cylinder and cone frustum forestry models across North American hardwood and softwood species.
Measure average diameter at the exact center of the log length.
1,259 kg • 1.26 Metric Tonnes
Preventing highway DOT weight fines, crane hoist overloads, and inaccurate sawmill procurement scaling.
Green timber carries immense sap weight. Loading an extra green oak log can push a tractor-trailer past the 80,000 lbs federal gross vehicle weight rating (GVWR), resulting in severe state highway patrol scale citations.
Skidding heavy sawlogs uphill can roll tractors or snap synthetic chokers if timber weight is underestimated. Knowing exact tonnage allows foresters to rig snatch blocks and adjust winching angles safely.
Comparing Doyle Rule scaling against International 1/4" board-foot yield reveals saw kerf penalties. Understanding true solid cubic volume prevents landowners from being short-changed on high-value hardwood logs.
Foresters estimate timber volume using geometric cylinder and frustum models, then apply empirical lumber recovery rules:
Where $D_{\text{mid}}$ is mid-diameter (in), $L$ is length (ft), $\rho$ is density (lb/ft³), and $k_{\text{bark}}$ is the bark factor (typically 1.10).
The Doyle rule heavily discounts small logs due to slab and sawdust allowances. The International 1/4" rule offers the most mathematically accurate commercial lumber recovery estimate.
Certified green vs air-dried densities across primary commercial sawlog species.
| Tree Species | Green Density (lb/ft³) | Seasoned Density (lb/ft³) | Weight Loss (Drying) | Commercial Uses |
|---|---|---|---|---|
| White Oak | 63 | 47 | -25.4% | Whiskey barrels, heavy crane mats, flooring |
| Red Oak | 63 | 44 | -30.1% | Railroad ties, cabinetry, structural timber |
| Hickory / Pecan | 64 | 50 | -21.9% | Tool handles, drumsticks, barbecue smoke wood |
| Sugar / Hard Maple | 56 | 44 | -21.4% | Gymnasium floors, bowling pins, fine furniture |
| Southern Yellow Pine | 55 | 36 | -34.5% | Dimension framing lumber, utility poles, trusses |
| Douglas Fir | 40 | 32 | -20.0% | Heavy timber framing, glulam beams, plywood |
| Western Red Cedar | 32 | 23 | -28.1% | Siding, shingles, sauna cladding, outdoor decking |
Examine the bark and end-grain. Hardwoods like oak weigh almost double lightweight softwoods like cedar.
Measure total length in feet. Use forestry calipers or diameter tape to measure both the butt and small-end tops inside the bark.
Determine if freshly felled (green, high sap content) or dried. Add a 10% to 15% allowance for rough outside bark.
Compare total tonnage against skidder winches, log loader grapples, and maximum highway semi-trailer payloads.
Pre-loaded green and seasoned densities for Oak, Pine, Maple, Cedar, Fir, Birch, and Ash timber species.
Accurately models natural tree taper from trunk base to top diameter rather than assuming a simple cylinder.
Converts raw log volume into commercial sawlog lumber yields under standard forestry scaling rules.
Calculates total log weight and trailer axle loading to ensure strict compliance with highway transport limits.
Technical wood science answers verified against USDA Forest Service guidelines.
A fresh-cut green white or red oak log measuring 16 feet long with an average diameter of 18 inches weighs approximately 1,890 to 2,050 lbs (approx. 1 US short ton) including bark. If the diameter increases to 24 inches, the weight surges to roughly 3,500 to 3,800 lbs.
Green timber contains bound water in cell walls plus free water in cell cavities, often reaching moisture contents of 60% to 100%+. As wood seasons to air-dry equilibrium (~12% to 15% moisture content), it sheds 25% to 35% of its total weight purely through water evaporation.
A typical tandem-axle semi logging truck carries a legal payload between 48,000 and 52,000 lbs (approx. 24 to 26 US tons). For heavy green hardwoods (e.g. 2,500 lbs per 16-ft log), a legal load is limited to roughly 18 to 22 logs to prevent highway axle overload violations.
The Huber formula (using midpoint cross-sectional area) is generally more accurate than Smalian's formula because Smalian consistently overestimates volume on logs with significant butt swell. When both small-end and large-end diameters are known, the cone frustum formula provides an exact geometric volume.
The Doyle Log Rule formula is: Board Feet = ((D - 4) / 4)² × L, where D is small-end diameter inside the bark in inches, and L is log length in feet. For example, a 16-foot log with an 18-inch top diameter yields ((18 - 4) / 4)² × 16 = (3.5)² × 16 = 196 board feet.
A standard cord of wood measures 128 stacked cubic feet, containing approximately 80 to 85 cubic feet of solid wood. A cord of green white oak or hickory weighs between 4,800 and 5,400 lbs. When seasoned, the same cord drops to between 3,500 and 3,900 lbs.
