StoneRiver Rock Calculator

River Rock Calculator

Calculate exactly how much decorative river rock you need for garden beds, dry creek beds, pathways, and water features. Get instant estimates in tons with material costs.

Project Dimensions

Recommended: 10% for irregular areas and borders

Ready to calculate

Enter your project dimensions

River Rock Sizes & Coverage

Small (1-2")

90 sq ft/ton

$80/ton • Pathways, borders

Medium (2-4")

75 sq ft/ton

$100/ton • Garden beds, mulch alternative

Large (4-8")

60 sq ft/ton

$120/ton • Water features, focal points

Cobble (6-12")

50 sq ft/ton

$150/ton • Dry creek beds, edging

Polished (1-3")

85 sq ft/ton

$180/ton • Premium decorative

Expert Contributors

Why expert review matters

Every calculator is reviewed by certified professionals to ensure accuracy.Hawkin's CCP, CEP certification ensures professional-grade precision.

Coverage by Depth (sq ft per ton)

2" deep

Small: 90 ft²

Medium: 75 ft²

Large: 60 ft²

3" deep

Small: 60 ft²

Medium: 50 ft²

Large: 40 ft²

4" deep

Small: 45 ft²

Medium: 38 ft²

Large: 30 ft²

6" deep

Small: 30 ft²

Medium: 25 ft²

Large: 20 ft²

Pro Tips

  • Install landscape fabric underneath to prevent weed growth and keep rocks from sinking into soil
  • Mix 2-3 rock sizes together for a more natural, organic look in garden beds and creek beds
  • Create a 4-inch deep steel or aluminum edging border to keep river rock from migrating into lawn
  • Rinse dusty river rock with a garden hose after installation to reveal true colors

Common Questions

How much river rock do I need?

Calculate L × W × depth (ft), divide by 27 for cubic yards, multiply by 1.3 density for tons.

How much does a ton cover?

At 2" deep: small rock covers 90 sq ft, medium 75 sq ft, large 60 sq ft per ton.

How deep should river rock be?

2-3" for ground cover, 3-4" for pathways and beds, 4-6" for dry creek beds.

River rock vs pea gravel?

River rock (1-4") for visual impact, pea gravel (¼-½") for walking surfaces.

How the Calculator Works

The calculator multiplies your project's length, width, and desired depth to determine total cubic yards needed. It then converts cubic yards to tons using the density for your selected river rock size. Larger rocks have lower density due to more air gaps between stones. We add your selected overage percentage to ensure complete coverage.

Formula

Cubic Yards = (Length × Width × Depth) ÷ 324

Tons = Cubic Yards × Rock Density × (1 + Waste %)

Quick Reference

Small rock density
1.35 t/yd³
Medium rock density
1.30 t/yd³
Large rock density
1.25 t/yd³
Delivery minimum
1-2 tons typical
Bag coverage
~3 sq ft at 2"