How this calculator works
It calculates the volume from your area and depth, converts to cubic yards, then to tons using a typical river rock weight of about 1.4 tons per cubic yard.
Worked example — a 15 ft × 10 ft bed at 2 inches:
150 × (2 ÷ 12) = 25 cubic feet → ÷ 27 = 0.93 cubic yards → about 1.3 tons.
How deep for river rock?
A 2-inch layer covers the ground for decorative beds; go 3–4 inches for drainage areas or to fully hide landscape fabric.
Frequently asked questions
How many tons of river rock per cubic yard?
About 1.4 tons, similar to gravel.
How deep should river rock be?
2 inches for decoration, 3–4 inches for drainage or coverage.
Planning a landscaping project
Measure each section separately when a bed or lawn is not a perfect rectangle, then add the sections together. Depth, moisture, compaction, and the way a supplier loads material can change the final quantity, so use the result as a purchasing estimate and confirm the supplier's coverage information.
How to use this estimate
- Measure the project in the units shown and recheck your measurements before ordering.
- Use the waste allowance as a planning buffer, not as a substitute for a detailed material takeoff.
- Compare the result with the package yield, coverage, or weight listed by your supplier.
- Prices are user-entered estimates and may change by location, product, delivery, and season.
Accuracy and limitations
Calculapedia provides educational planning estimates. It does not inspect your site, select products, guarantee quantities, or replace a contractor, engineer, architect, building official, or supplier. Confirm the final quantity and any safety or code requirements before buying or building.