Formula
How this estimate works
cubic yards = area x depth in feet / 27; tons = cubic yards x density
A 220 sq ft river rock area at 3 in deep with 10% waste needs about 2.24 cubic yards before supplier rounding.
River rock volume
River rock is estimated from area and depth, then converted from cubic yards to tons using a density estimate. Actual tonnage varies with stone size and moisture.
Decorative rock planning
River rock is often used for visible landscape areas, drainage features, and borders. Larger rock sizes may need more depth for consistent coverage.
Assumptions used
- River rock density is estimated at 1.35 tons per cubic yard.
- Stone size and moisture can change actual weight.
- Depth is assumed to be even across the measured area.
Before you order materials
- Choose depth based on rock size and desired coverage.
- Use edging or borders where rock could migrate.
- Ask the supplier for product-specific tons per cubic yard.
Frequently asked questions
How deep should river rock be?
Decorative river rock often uses around 2 to 4 inches, but larger stones may need deeper coverage.
How many tons of river rock do I need?
Tons depend on area, depth, and density. Enter your project size and use your supplier's density when available.
Should I use landscape fabric under river rock?
Many projects use fabric to reduce weed growth and keep rock separated from soil, but drainage and plant needs vary.