River Rock Calculator
How much river rock for the dry creek bed or flower bed border?
How this is calculated
- Volume in cubic feet = length × width × (depth ÷ 12)
- Cubic yards = cubic feet ÷ 27, plus the settling allowance
- US tons = cubic yards × 2500 ÷ 2000 (typical river rock density)
Common questions
How much river rock do I need for a 10×10 bed?
A 10 × 10 bed at 2 inches takes about 0.62 cubic yards — 0.85 tons with the 10% allowance at river rock's ~2500 lb/yd³. River rock is sold by weight but laid by depth, which is exactly what this calculator converts.
What size river rock should I use?
1-2 inch stones are the versatile middle: they stay put on moderate slopes, look natural in beds, and are easy to walk on. 3-5 inch stones make statement dry creek beds but are hard to spread evenly. Under 1 inch ("pebbles") scatters and migrates — it needs edging like pea gravel.
How deep should a dry creek bed be?
3-4 inches of rock over landscape fabric in a shallow swale handles normal rainwater from a roof downspout. The rock layer is decoration and armor — the slope of the swale does the actual drainage work, so make sure the bed has somewhere to send water.
How many tons in a cubic yard of river rock?
About 1.25 tons (2500 lb/yd³) — lighter than crushed stone because the rounded stones pack with air gaps. One cubic yard covers 324 sq ft at 1 inch, or 108 sq ft at the typical 3-inch decorative depth.
Do I need landscape fabric under river rock?
Yes — rock beds without fabric grow weeds through the stone within a season, and pulling weeds from river rock is miserable. Use a quality woven geotextile (not flimsy plastic), overlap seams 6 in, and pin edges; the fabric also keeps the rock from sinking into clay soil over time.