River Rock Calculator
Enter area dimensions to calculate river rock needed.
River Rock Formula
Measure the area, enter depth (typically 2-4 inches for ground cover), and the calculator returns cubic yards and estimated tons for river rock.
Understanding River Rock
River Rock Sizes and Applications
River rock is naturally tumbled stone with smooth, rounded surfaces, formed by decades of water erosion. It is available in sizes from 3/8 inch pebbles to 12-inch boulders.
| Size | Diameter | Primary Use | Coverage per CY at 3 in |
|---|---|---|---|
| Small Pebbles | 3/8 - 3/4 in | Pathways, ground cover | 108 sq ft |
| Medium River Rock | 1 - 3 in | Landscape beds, dry creek beds | 90 sq ft |
| Large River Rock | 3 - 5 in | Borders, water features | 70 sq ft |
| Cobblestone | 5 - 12 in | Accent walls, focal points | 50 sq ft |
River Rock for Drainage Solutions
- French drains: 1-2 inch river rock surrounding a perforated pipe, 0.5 cubic yards per 10 linear feet.
- Dry creek beds: 2-4 inch river rock in a shallow graded channel to redirect surface water.
- Downspout drainage: A splash pad of 2-3 inch river rock at each downspout outlet.
- Swales: Broad channels lined with 3-5 inch river rock to slow stormwater runoff.
River Rock Cost Factors
River rock costs - per cubic yard for common varieties and - for specialty colors. Buying in bulk (5+ cubic yards) reduces per-unit cost by 15-25% compared to bagged river rock from home centers.
River Rock Calculator FAQ
At 2 inches deep: 0.006 cubic yards per sq ft. At 3 inches: 0.009 cubic yards per sq ft. Multiply by total area and add 10% for waste.
River rock weighs approximately 2,700 lbs (1.35 tons) per cubic yard. A tandem dump truck can carry 7-10 cubic yards per load.
Use 2 inches for small pebbles in decorative beds, 3 inches for medium river rock, and 4-6 inches for drainage applications and dry creek beds.
Yes, river rock is excellent for drainage. Its rounded shape creates consistent void spaces that allow water to flow freely. It is preferred for French drains and dry creek beds.
Buy in bulk from a local quarry at - per cubic yard. Bagged river rock from home centers costs 3-5 times more per volume.
Yes, river rock is excellent around foundations because it does not retain moisture like mulch. Maintain a 6-inch gap between rock and siding.