River Rock Calculator
Calculate volume and weight of river rock needed for landscaping.
Formula
Volume (cu yd) = L × W × D(ft) ÷ 27; Tons = cu yd × 1.35
- River rock density ≈ 1.35 short tons/cu yd (varies by size).
- Common landscaping depth: 2–3 in (decorative); 4–6 in (drainage).
- Add 10% for waste and settling.
20 ft × 10 ft, 3 in deep
Inputs
- Area Length: 20 ft
- Area Width: 10 ft
- Depth: 3 in
20 × 10 × 0.25 = 50 cu ft ÷ 27 = 1.85 cu yd × 1.35 = 2.50 tons.
Frequently asked questions
How deep should river rock be for a dry creek bed?
4–6 inches is typical for a dry creek bed. For purely decorative mulch replacement, 2–3 inches is sufficient.