River Rock Calculator
Calculate how much river rock or decorative stone you need by volume and weight, with cost estimate.
Results
Visualization
How It Works
River rock is a smooth, rounded natural stone prized for its appearance in dry creek beds, borders, and drainage features. It is heavier than most other ground covers at roughly 1.5 tons per cubic yard, so accurate calculation prevents overspending.
The Formula
Volume (cu ft) = Length x Width x Depth / 12
Cubic Yards = Volume / 27
Tons = Cubic Yards x 1.5
Cubic Yards = Volume / 27
Tons = Cubic Yards x 1.5
Variables
- L — Length of the area in feet
- W — Width of the area in feet
- D — Desired depth in inches
- 1.5 — Approximate weight of river rock in tons per cubic yard
Example
A 15 ft x 8 ft dry creek bed at 3 inches deep needs 30 cu ft = 1.11 cubic yards = 1.67 tons. At $100/ton that costs about $167.
Tips
- Larger river rock (3-5 inch diameter) requires a deeper layer, usually 3-4 inches minimum.
- Smaller river rock (1-2 inch) can be laid at 2 inches deep for ground cover.
- Use landscape fabric beneath river rock to prevent weeds and keep stones from sinking.
- River rock does not decompose like mulch, so it is a one-time purchase that lasts for decades.
- Delivery of heavy stone may require equipment access, so verify truck can reach the site.