Topsoil & Mulch Calculator
Calculate topsoil, mulch, compost, or bark volume in cubic meters and weight in tonnes. Automatically adjusts for material settling.
Part of the Landscaping & Site Work calculators — see all tools in this category.
Current result
Total area to be covered
50-75mm for mulch, 100-150mm for topsoil
Auto-set from material. Override if needed.
Typical waste is 5-10% for landscape materials
Optional: material cost per cubic meter
Optional: material cost per tonne
Results
With settling & waste
Total weight to order
Area × Depth
Material density
Calculation: Base 1 m³ × Settling 1.2 × Waste 1.05 = 1.26 m³
How it works and assumptions
This calculator helps you determine the volume and weight of topsoil, mulch, compost, or bark needed for your landscaping project. It automatically accounts for material settling to ensure you achieve your target depth.
How to Use
- Enter the area to cover in square meters
- Enter the desired depth (50-100mm typical for mulch, 100-150mm for topsoil)
- Select your material type - each has different density and settling rate
- The calculator automatically applies the settling factor for your material
- Order the displayed volume to achieve your target depth after settling
Recommended Depths
| Application | Recommended Depth |
|---|---|
| Weed suppression (mulch) | 50-75mm |
| Garden mulch (general) | 75-100mm |
| New lawn (topsoil) | 100-150mm |
| Garden bed prep (topsoil) | 150-200mm |
Understanding Settling Factor
Unlike compacted aggregates, landscape materials settle naturally over time. The settling factor accounts for this:
- Topsoil: 1.2 factor (settles ~20%)
- Compost: 1.3 factor (settles ~30%)
- Bark Mulch: 1.25 factor (settles ~25%)
- Wood Chips: 1.2 factor (settles ~20%)
Formula
Base Volume: Area (m²) × Depth (m)
Volume to Order: Base Volume × Settling Factor × (1 + Waste %)
Weight: Volume to Order × Density (t/m³)
Frequently Asked Questions
Sources and revision
Page revision: 2026-10-12