River Gravel (20mm)

Known for its earthy colouring and rounded shape, 20mm river gravel is a smooth and versatile decorative stone commonly used for:

• Garden beds and landscaping
• Decorative pathways
• Around trees and shrubs
• Drainage applications
• Water features and ponds
• Driveways and feature areas

Because river gravel has a rounded shape, it doesn't compact as firmly as crushed stone, so it may shift more under vehicle traffic. It is better suited to light-use areas such as garden paths, decorative driveways with low traffic, garden beds, and water features.

If you're looking for a more stable surface for a heavily used driveway, we generally recommend a crushed decorative stone or drainage gravel instead.

To calculate how much 20mm river gravel you need for your project, measure the length and width of the area where the stones will be placed.

Next, determine the desired depth of the stones. The required depth will vary depending on your project and the area you need to cover.

Once you have your length, width, and depth measurements, you can use our cubic metre calculator above or calculate the volume manually using the following formula:
Volume = Length × Width × Depth

Recommended Depth: As a general guide, we recommend laying decorative stones at a depth of 40–50mm. However, the ideal depth will depend on your project and the size of the stones. Larger stones may require a deeper layer for even coverage, while smaller stones can often be laid slightly thinner.

River gravel consists of smooth, rounded stones that create a natural, decorative look, while crushed drainage gravel has a crushed surface that interlocks, making it more stable for driveways, pathways, and high-traffic areas.

Both products provide excellent drainage and are suitable for diverting water. However, crushed drainage gravel is generally the better choice for areas with heavy water flow.