Example 1 — Lawn area
- 12 × 8 × 0.15 m
- 1200 kg/m³
- +5% waste
15.12 m³ · 18.14 t
About 150 mm topsoil for a new lawn.
Topsoil requirement
Estimate topsoil for lawns, beds or levelling — layer depth, waste and tonnes or bags.
Topsoil ≠ compost ≠ fill dirt. Match density to what you are buying. Related: floor / plot area, gravel.
Results
Enter data and click Calculate.
How results are calculated
V = length × width × depth × (1 + waste/100). Mass = V × topsoil density. Optional bags / bulk bags.
Density stays in kg/m³ even with US length units — common for bulk deliveries. Mass is an estimate: moisture and compaction can change it.
How to use this calculator
- Enter area dimensions and layer depth.
- Set waste % for settlement and spreading.
- Pick a soil density preset or custom kg/m³.
- See volume, tonnes and cost.
Practical tips
- Lawn: often about 100–150 mm of quality topsoil over prepared subgrade.
- Beds: often 200–300 mm — volume rises quickly with depth.
- Levelling: enter average fill depth; split large slopes into zones.
Usage examples
Example 2 — Garden beds
- 4 × 2 × 0.3 m
- 1100 kg/m³
- +10% waste
2.64 m³ · 2.90 t
Deeper light soil for flower beds.
Example 3 — Levelling strip
- 20 × 1.5 × 0.1 m
- 1400 kg/m³
- +5% waste
3.15 m³ · 4.41 t
A strip along a fence — denser fill soil.
Frequently asked questions
How much topsoil for a lawn?
Often about 100–150 mm of quality topsoil over prepared subgrade. Enter length, width and that depth.
How deep for garden beds?
Beds often need 200–300 mm. Deeper beds use more volume quickly — check the result in tonnes too.
Topsoil vs compost vs fill dirt?
Topsoil is screened growing soil. Compost is organic amendment. Fill dirt is for bulk levelling and may not grow turf well.
How are tonnes calculated?
Tonnes = volume × density (kg/m³) / 1000. Screened soils are lighter than compacted fill.
Should I add overage?
Yes — 5–10% covers settlement, uneven ground and spreading losses.
Bulk bags or tipper loads?
Small gardens: bulk bags (~0.5 m³). Large lawns: tipper loads by the tonne may be cheaper.
Can I use this for levelling only?
Yes — enter the average fill depth. For large level changes, split the area into zones with different depths.
How is cost estimated?
Optional price per m³, per tonne, per bag or per bulk bag. Delivery and spreading labour are extra.