Topdressing Calculator
Work out how many cubic metres (and roughly how many tonnes) of topdressing you need from your lawn area and depth.
What to order
Enter the area and depth.
How it works
Topdressing is spreading a thin layer of sand or soil mix over the lawn to fill hollows and level the surface. Volume is simple: area times depth. Weight depends on the material, so this calculator shows the density it assumes and lets you change it.
Sources: Australian Native Landscapes lists indicative sand weights of 1.3 to 1.5 tonnes per cubic metre and notes they vary with grade and moisture.
Worked example
100 m² at 10 mm deep is 100 × 0.01 = 1 m³. With 10% extra for spillage, order 1.1 m³. At an assumed 1.4 tonnes per m³ that is about 1.5 tonnes. Ask your supplier for the actual density of their product.
What you enter
- Area in m²
- Depth in mm
- Extra for spillage (%)
- Bulk density in tonnes per m³ (editable)
What you get
- Volume in m³
- Approximate weight in tonnes
Assumptions
- Bulk density is pre-filled at 1.4 t/m³, an assumption based on indicative supplier figures of 1.3 to 1.5 t/m³ for sand. Density varies with the material and how wet it is, so ask your supplier and change it.
Questions
Why do suppliers sell by the tonne and the cubic metre?
Volume tells you how much ground you can cover. Weight tells you what a trailer or truck can carry. The conversion depends on the material and its moisture.
How deep should I topdress?
That depends on the job and your grass type. See the renovation guide, and never bury the leaf completely.