About this calculator
Topsoil for a new lawn, raised levels or planting beds, with a settling allowance.
How it’s calculated
Volume = area × depth × (1 + settling). Loose topsoil settles 15–20% once it is firmed and watered.
Worked example
With these inputs:
- Area shape
- Rectangle
- Length
- 6 m
- Width
- 3 m
- Depth
- 100 mm
- Material
- Screened topsoil / turf underlay
- Extra for settling
- 15%
the result is:
- Volume
- 2.07 m³
- Area
- 18 m²
- Approx. weight
- 2.69 t
- 25 L bags
- 83 bags
Tips from the trade
- 100–150 mm of turf underlay under new turf.
- Order screened soil. Unscreened soil comes with stones and roots.
Results are estimates for planning and pricing. Check quantities against your drawings, the manufacturer’s data and the NCC and Australian Standards before ordering.