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Topsoil Cubic Metre Calculator

Determine soil and compost volume in cubic metres (m³) and metric tonnes (t) for lawn leveling, garden bed creation, and earth filling. Automatically includes a 15% soil settlement allowance.

Topsoil & Lawn Dressing Volume (m³)

Real-time volumetric & tonnage modeling (SABS & ISO Metric SI compliant)

Standard residential concrete slabs are typically 100 mm to 150 mm thick.

2.40 t/m³ (2,400 kg/m³)
+15%
0% (Exact void)+5%+10% (Recommended)+15%+25% (Excavation)
Gross Volume (Order Quantity)Live Calc
8.250m³

Includes +10% waste over net physical volume.

Net Physical Void7.500m³
Total Liquid Volume8,250L
Total Weight (t)19.80tonnes
Ready-Mix Deliveries~1.4trucks (6m³)
Imperial EquivalentsUS Customary
Cubic Yards: 10.79 yd³
Cubic Feet: 291.35 ft³
Mathematical Derivation & Proof
SI Metric Model

Formula: V_net = Length × Width × Depth

V_net = 10.000 m × 5.000 m × 0.150 m = 7.500 m³

1. Normalizing inputs to metres: L = 10.000 m, W = 5.000 m, D = 0.150 m
2. Net volume: 10.000 × 5.000 × 0.150 = 7.500 m³
3. Factoring +10% waste allowance: 7.500 × 1.10 = 8.250 m³
4. Total mass @ 2.40 t/m³ (Concrete): 8.250 × 2.40 = 19.80 tonnes
5. Standard 6 m³ truckloads: 8.250 / 6 = ~1.4 loads (order 2 trucks)

Understanding Soil Settlement & Bulk Densities

The engineering mathematics behind volumetric measurement, compaction allowances, and ready-mix batching.

01

Normalize to Metres (m)

Slab thickness and trench depths are commonly specified in millimetres (e.g., 150 mm) or centimetres (15 cm). Convert all dimensions to metres before multiplying:

Depth (m) = mm ÷ 1,000
150 mm ÷ 1,000 = 0.150 m
02

Solve Net Volume (m³)

Multiply length by width and depth to determine the net physical void space. For cylinders (round tanks, circular slabs), multiply base area ($\pi r^2$) by height:

V_net = L × W × D
10.0 m × 5.0 m × 0.15 m = 7.50 m³
03

Apply Compaction & Waste

Excavated subgrades settle, formwork flexes under hydraulic pressure, and pumps retain residual mix. Always factor 5% to 15% extra for realistic batching:

V_order = V_net × (1 + Waste %)
7.50 m³ × 1.10 (+10%) = 8.25 m³

Topsoil & Turf FAQs

Common questions regarding metric cubic metre calculations, bulk densities, and material batching.

How do you calculate cubic metres of topsoil for a lawn?
Measure your lawn length and width in metres to find total square metres (m²). Multiply by desired topsoil depth in metres. For a 100 m² lawn with a 25 mm top-dressing layer: 100 m² × 0.025 m = 2.50 m³ of soil.
How much does one cubic metre of topsoil weigh?
Dry, screened garden topsoil weighs approximately 1.20 to 1.30 metric tonnes per cubic metre (1,200 to 1,300 kg). Damp or uncompacted organic loam typically weighs closer to 1.40 tonnes per m³.
How much does loose soil settle after watering?
Loose topsoil settles by 15% to 20% after watering and natural rainfall compaction. Always add 15% extra volume when ordering soil for new lawn preparation or filling raised vegetable beds.