Soil & Gravel Calculation Formula
Volume + Compaction: Volume × (1 + Compaction % ÷ 100)
Weight: Volume (with compaction) × Density (t/m³)
Densities: Topsoil 1.3, Garden Soil 1.2, Sand 1.6, Gravel 1.8, Crushed Rock 1.5, Road Base 2.0, Mulch 0.4 t/m³
Note: Add a compaction factor when the material will be compacted after placement (e.g. road base 10–15%).
Soil & Gravel Calculator — Volume, Weight & Cost
Australians purchase over 30 million cubic metres of landscape and construction aggregates annually (CCAA, 2024). This calculator determines exact volume, weight, truck loads, and cost for soil, gravel, sand, mulch, and other bulk materials.
Material Densities (t/m³)
| Material | Density |
|---|---|
| Topsoil | 1.1 |
| Garden Soil | 1.2 |
| Sand | 1.5 |
| Gravel (Loose) | 1.5 |
| Crushed Rock | 1.6 |
| Road Base | 1.75 |
| Mulch | 0.4 |
| Concrete (Wet) | 2.4 |
Depth Guide
| Application | Depth |
|---|---|
| Garden Mulch | 50–75mm |
| Lawn Topsoil | 100–150mm |
| Driveway Base | 100–150mm |
| Paving Base | 75–100mm |
Formulas
- Volume = Area × Depth
- With compaction = Vol × (1 + Compaction %). Typical 10–25% for gravel.
- Weight = Volume × Density
- Truck loads = Volume / Truck Capacity (6–12 m³)
Frequently Asked Questions
How much soil do I need?
Area × depth in metres. 10m×5m at 200mm: 10×5×0.2 = 10m³. Add 10% for settlement = 11m³.
How many m3 in a truck?
Standard tipper: 6–8m³. Tandem: 10–12m³. Semi: up to 20m³.
Gravel cost per m3?
$50–$90/m³ supply + $100–$200 delivery. Full truck loads are more cost-effective.
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