Wood Weight Calculator (kg, Australia): Timber Weight by Species in Metric
Australian timber weight is calculated in metric as Weight (kg) = Width (m) x Thickness (m) x Length (m) x Density (kg/m3) — enter your dimensions in millimetres and metres and choose from common Australian species like Radiata Pine, Tasmanian Oak, Jarrah, and Spotted Gum for an instant weight in kilograms, useful for trailer, ute, or van payload planning.
Quick Answer
Australian timber weight is calculated in metric as Weight (kg) = Width (m) x Thickness (m) x Length (m) x Density (kg/m3) — enter your dimensions in millimetres and metres and choose from common Australian species like Radiata Pine, Tasmanian Oak, Jarrah, and Spotted Gum for an instant weight in kilograms, useful for trailer, ute, or van payload planning.
Wood Weight Calculator (kg, Australia): Timber Weight by Species in Metric
Enter your values below for an instant result, then see the formula, worked example, and common mistakes.
Enter your timber dimensions in metres/millimetres, then click calculate.
How to Use This Calculator
Australian softwoods like Radiata and Monterey Pine are lighter (roughly 510-545 kg/m3 seasoned); Australian hardwoods like Jarrah, Spotted Gum, and Silvertop Stringybark are considerably denser (835-1,100+ kg/m3).
Standard Australian structural timber lengths are commonly 2.4, 3.0, 3.6, 4.2, 4.8, 5.4, and 6.0 m.
Common structural sizes include 70×35, 90×35, 90×45, and 140×45 mm (MGP-graded pine); hardwood decking and furniture stock varies more widely.
Seasoned (kiln- or air-dried) timber is the standard reference condition for density tables. Green (freshly milled, unseasoned) timber retains far more moisture and can weigh 30-60% more than the same piece seasoned.
Useful for checking a full pack or trailer load against a vehicle’s GVM (Gross Vehicle Mass) or payload rating before transport.
Formula
Weight (kg) = Width (m) x Thickness (m) x Length (m) x Density (kg/m3). Since Australian timber is typically sold with width and thickness in millimetres, divide each by 1,000 to convert to metres before multiplying. Green (unseasoned) timber should have density increased by roughly 30-60% to account for retained moisture, since freshly milled timber has not yet dried to its stable seasoned weight.
Reference Table: Common Australian Timber Densities
| Species | Density (kg/m3, seasoned) | Type | Typical use |
|---|---|---|---|
| Radiata Pine | ~510 | Softwood | Framing, structural (MGP grades) |
| Monterey Pine | ~545 | Softwood | Framing, general construction |
| Qld Maple | ~575 | Hardwood | Furniture, joinery |
| White Cypress Pine | ~675 | Softwood | Termite-resistant flooring, cladding |
| Tasmanian Oak / Victorian Ash | ~700 | Hardwood | Flooring, furniture, joinery |
| Jarrah | ~835 | Hardwood | Decking, flooring, outdoor structures |
| Silvertop Stringybark | ~860 | Hardwood | Structural, decking |
| Spotted Gum | ~1,100 | Hardwood | Decking, heavy structural, flooring |
Common Mistakes to Avoid
- Mixing millimetres and metres without converting — width and thickness are usually specified in mm on Australian timber, but the density formula requires metres throughout for the result to come out in kg.
- Using a seasoned density figure for green (freshly milled) timber — green hardwood in particular can weigh 30-60% more than its seasoned weight due to retained sap and moisture.
- Assuming all pine is the same weight — Radiata and Monterey Pine are both common Australian plantation softwoods but have measurably different densities, and MGP-graded structural pine can vary by supplier.
- Forgetting to account for total pack weight when loading a trailer or ute — multiply per-length weight by quantity and check against your vehicle’s GVM/payload rating, since a full pack of dense hardwood can add up quickly.
When the Estimate May Be Wrong
Density figures above are typical averages for seasoned (kiln- or air-dried) timber and can vary based on growth region, moisture content at time of purchase, and individual board density variation within a species. For precise structural or engineering applications, use the specific grade stamp and supplier documentation for your timber rather than average species density alone.
FAQs
How do you calculate timber weight in kg in Australia?
Multiply width in metres by thickness in metres by length in metres by the species’ density in kg per cubic metre. Since Australian timber sizes are usually given in millimetres, divide each by 1,000 first.
How much heavier is green timber than seasoned timber?
Green (freshly milled, unseasoned) timber can weigh approximately 30 to 60% more than the same timber once seasoned (dried), due to retained moisture content.
What is the density of Jarrah compared to Radiata Pine?
Jarrah, a dense Australian hardwood, has a density of roughly 835 kg/m3, compared to Radiata Pine (a common structural softwood) at roughly 510 kg/m3 — Jarrah is more than 60% heavier by volume.
Why does timber weight matter for transport in Australia?
Knowing accurate timber weight helps ensure a trailer, ute, or van load stays within its rated GVM (Gross Vehicle Mass) and payload limits, which is both a safety and legal compliance requirement.
Sources and Methodology
Australian timber species density figures (Radiata Pine ~510 kg/m3, Monterey Pine ~545 kg/m3, Qld Maple ~575 kg/m3, White Cypress Pine ~675 kg/m3, Tasmanian Oak/Victorian Ash ~700 kg/m3, Jarrah ~835 kg/m3, Silvertop Stringybark ~860 kg/m3) sourced from Queensland Department of Agriculture and Fisheries (QTimber) wood density and hardness guide and corroborated against Australian Wood Review’s “Density in Wood” reference. Spotted Gum density (~1,100 kg/m3) reflects standard Australian hardwood density references for the species. Green-vs-seasoned moisture weight increase (30-60%) follows standard timber industry moisture-content guidance.
