River Rock Calculator
Enter your area and depth to get cubic yards and tonnage of river rock for beds, borders, drainage swales, and dry creek beds.
Small stone (¾–1″): 2″ deep. Larger stone (2–4″): 3–4″ deep.
How it works
Length × width × depth (in feet), divided by 27, gives cubic yards. Rounded river rock packs looser than crushed gravel, so we use about 1.25 tons per cubic yard for the weight estimate.
Formula: (Length × Width × Depth÷12) ÷ 27 = cubic yards (× 1.25 = tons)
Good for
- Bed toppings and borders
- Dry creek beds and swales
- Downspout splash zones
- Low-maintenance ground cover
Tips
- Lay landscape fabric underneath — river rock is miserable to separate from soil later.
- Match depth to stone size: cover at least twice the diameter of the largest stone.
- Rounded stone rolls underfoot; use crushed gravel for paths you'll walk on.
References
Estimates use standard industry volume math. Cross-check your numbers against the pros:
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Open calculator →River Rock Calculator FAQ
How much does river rock weigh per cubic yard?
Around 2,400–2,600 lb per cubic yard (about 1.25 tons), a bit lighter than crushed stone because rounded rock packs with more voids.
How deep should river rock be?
Use a layer roughly twice the diameter of the stone: 2 inches for ¾–1″ rock, 3–4 inches for 2–4″ rock, so the ground never shows through.
Do I need landscape fabric under river rock?
Strongly recommended. It keeps stone from sinking into soil, blocks most weeds, and makes future changes far easier.