Decorative & Hardscape · Contractor Estimation Tool

River Rock Coverage & Tonnage Calculator

Calculate 1–3 inch and 3–5 inch washed river rock in tons and cubic yards for flower beds, tree rings, and dry creek beds.

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How the River Rock Coverage & Tonnage Calculator Works

Decorative river rock or ornamental stone (1" to 3" diameter) with void spaces between stones for attractive xeriscaping and drainage. Our River Rock Coverage & Tonnage Calculator computes exact geometric volume in cubic feet and cubic yards, then converts volume into US short tons (2,000 lbs) using the typical bulk density of Landscape Rock (Washed River Rock 1" – 3") (2,430 lb/yd³ or 1.22 tons/yd³).

Mathematical Formula for River Rock:
1. Area (sq ft) = Length (ft) × Width (ft)
2. Volume (cu ft) = Area (sq ft) × [Depth (inches) ÷ 12]
3. Volume (cu yd) = Volume (cu ft) ÷ 27
4. Recommended Volume = Base Volume × (1 + 10% Ordering Adjustment)
5. Estimated Tons = Recommended Cubic Yards × 1.22 tons/yd³

Step-by-Step Worked Example

Example Project: 35 ft × 5 ft Area at 3 Inches Depth (+10% Adjustment)

Surface Area: 35 ft × 5 ft = 175 sq ft.
Base Volume: 175 sq ft × (3 ÷ 12) = 43.8 cu ft (1.62 cubic yards).
With +10% Ordering Adjustment: 1.62 yd³ × 1.10 = 1.78 cubic yards.
Weight in US Short Tons: 1.78 yd³ × 1.22 tons/yd³ = 2.17 tons (4,331 lbs).

Primary Applications & Contractor Best Practices

Xeriscaping and garden decorative ground cover: Engineered for reliable coverage, drainage stability, and long-term performance.
Foundation drip edges and splash guards: Engineered for reliable coverage, drainage stability, and long-term performance.
Dry creek beds and decorative swales: Engineered for reliable coverage, drainage stability, and long-term performance.
Tree rings and ornamental borders: Engineered for reliable coverage, drainage stability, and long-term performance.

Coverage & Tonnage Quick Reference Table (Landscape Rock (Washed River Rock 1" – 3"))

Estimated cubic yards and US short tons (including +10% ordering adjustment) across common project square footages:

Project Area	2" Depth	3" Depth	4" Depth	6" Depth
100 sq ft	0.83 t (0.68 yd³)	1.24 t (1.02 yd³)	1.65 t (1.36 yd³)	2.48 t (2.04 yd³)
250 sq ft	2.06 t (1.70 yd³)	3.09 t (2.55 yd³)	4.13 t (3.40 yd³)	6.19 t (5.09 yd³)
500 sq ft	4.13 t (3.40 yd³)	6.19 t (5.09 yd³)	8.25 t (6.79 yd³)	12.38 t (10.19 yd³)
1,000 sq ft	8.25 t (6.79 yd³)	12.38 t (10.19 yd³)	16.50 t (13.58 yd³)	24.75 t (20.37 yd³)
1,500 sq ft	12.38 t (10.19 yd³)	18.56 t (15.28 yd³)	24.75 t (20.37 yd³)	37.13 t (30.56 yd³)

Frequently Asked Questions

Multiply your project length (35 ft) by width (5 ft) to get area (175 sq ft). Multiply by depth in feet (3 in ÷ 12 = 0.25 ft) to get 43.8 cubic feet, then divide by 27 to get 1.62 base cubic yards. Adding a 10% ordering adjustment gives 1.78 yd³, which equals 2.17 US short tons at 2430 lb/yd³.

One cubic yard (27 cubic feet) of Landscape Rock (Washed River Rock 1" – 3") weighs approximately 2,430 pounds, or 1.22 US short tons (90 lbs per cubic foot). Typical regional quarry densities range between 2,250 and 2,650 lb/yd³.

For most river rock installations, a typical compacted depth is 3 inches (our default preset uses 3 inches). Always excavate soft organic topsoil and install woven or non-woven geotextile fabric before spreading aggregate.

At 1.22 tons per cubic yard, 1 US short ton equals 0.82 cubic yards (22.2 cu ft). That covers approximately 133 sq ft at 2" deep, 89 sq ft at 3" deep, and 67 sq ft at 4" deep.