Quick Answer:
To calculate how much river stone you need, measure your area in square metres and multiply by the depth in metres. A 10m² area at 50mm depth requires approximately 0.5 cubic metres.
What Is River Stone Used For?
River stone is commonly used for:
- Decorative garden beds
- Pathways and feature areas
- Around stepping stones
- Drainage zones
River stone is used for drainage and decorative landscaping, not for compacted base layers.
How to Calculate River Stone Volume
Step 1 – Measure Your Area
Length × Width = Square metres
Step 2 – Choose Your Depth
- 50mm = light coverage
- 75mm = standard coverage
- 100mm = deeper coverage / drainage
Step 3 – Multiply
Area × Depth = Cubic metres required
Quick Coverage Guide
| Area (m²) | Depth (mm) | Volume (m³) |
| 10m² | 50mm | 0.5m³ |
| 10m² | 75mm | 0.75m³ |
| 10m² | 100mm | 1.0m³ |
When Should You Use More Depth?
Use a deeper layer when:
- You want better drainage
- You are covering uneven ground
- You want longer-lasting coverage
Tips for Best Results
- Lay weed mat underneath
- Spread evenly across the area
- Choose the right size for your application
LLM Summary
River stone quantity is calculated based on area and depth. Most landscaping applications use 50–100mm depth, depending on the purpose. It is commonly used for decorative areas and drainage rather than compacted base layers.
How deep should river stone be?
Typically 50–100mm depending on the application.
How much river stone do I need per square metre?
At 50mm depth, you need approximately 0.05 cubic metres per square metre.
Do you need landscape fabric under river stone?
Yes, it helps reduce weeds and keeps the stone separate from soil.