Unit system:
Moisture mass factor (multiplies weight, not volume)
Preset state: —
FSP: —
Tip: If a preset density is already “green” or “air‑dry”, keep factor 1.00 or tweak slightly.
Per-species MC curves shape shrinkage below FSP. Diameter and length use separate species parameters.
| # | Species / Density | Formula | D₁ | D₂ | Dₘ | Length | Bark (thk) | Subtract Bark |
Qty | Vol (m³) | Weight (kg) | Weight (lb) | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Totals | 0.000 | 0 | 0 | ||||||||||
Diameters are over-bark unless “Subtract Bark” is checked. Bark thickness is per side.
Conversions: 1 in = 25.4 mm, 1 ft = 0.3048 m, 1 kg = 2.20462 lb, 1 short ton = 2000 lb.
Short tons (US): 0.000 | Metric tonnes: 0.000
Pallet loading
Pallets required: 0
Lorry/Truck loading
Loads required: 0
Formula Used
Log volume is calculated using standard forestry formulas. Let end areas be A₁ = π(D₁)²/4, A₂ = π(D₂)²/4, and mid-area Aₘ = π(Dₘ)²/4, with diameters in meters and length L in meters.
- Smalian:
V = L (A₁ + A₂) / 2— Good for tapered logs. - Huber:
V = L · Aₘ— Requires mid diameter; we estimate if blank. - Newton:
V = L (A₁ + 4Aₘ + A₂) / 6— Often most accurate. - Cylinder (avg D):
V = L · π( D̄² )/4whereD̄ = (D₁ + D₂)/2.
Weight is W = ρ · V · Qty · fₘ. Optional per‑species MC curves shrink diameters and length below FSP before areas and volume are computed.
How to Use
- Select unit system. Enter diameters and length of each log.
- Choose a species preset or set a custom density.
- Pick a volume formula. For Huber/Newton, add mid diameter if known.
- Optionally enable auto bark; edit per row or click “↺ preset”.
- Set moisture mass factor and, if needed, MC shrinkage options.
- Set quantity for identical logs. Add more rows as needed.
- Check ton and loading summaries. Export results to CSV or PDF.
Example Data
| # | Species | Formula | D₁ | D₂ | Dₘ | Length | Bark | Subtract | Qty | Units |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Pine (green) | Newton | 300 | 260 | 4.8 | 8 | Yes | 4 | mm/m | |
| 2 | Red Oak (green) | Smalian | 450 | 400 | 3.2 | 12 | Yes | 1 | mm/m | |
| 3 | Spruce (green) | Cylinder | 280 | 280 | 6.0 | 6 | Yes | 8 | mm/m |
Click “Load example data” to populate the table above into the calculator.
FAQs
Newton often provides excellent accuracy; Smalian is common for tapered logs; Huber is best when the mid diameter is known.
No. Densities vary by moisture, region, and temperature. Use “Custom” to match local conditions or supplier data.
We subtract twice the bark thickness from each diameter before computing areas. Bark thickness is taken per side.
We use species parameters and curve exponents to model trends. They are heuristics; for compliance use local standards or lab data.
We estimate mid area from end diameters for Huber/Newton when Dₘ is blank, using a root-mean-square diameter approximation.
Yes. Weight uses a mass factor; volume uses MC curves below FSP for diameter and length shrinkage prior to calculation.
Enter pallet and vehicle payload limits; we compute pallets and loads required from total weight. Adjust units to match your local constraints.