Estimate river rock for landscaping, dry river beds and drainage. Enter your area and depth to get cubic yards and tons instantly.
River rock weighs about 1.4 tons per cubic yard. For a dry river bed, go 2 to 4 inches deep.
River rock is sold by the cubic yard or the ton, so convert your area and depth to volume first. The formula is length times width times depth in feet, divided by 27. A 20 by 4 foot dry creek bed at 2 inches deep is 20 × 4 × 0.167 ÷ 27 = 0.49 cubic yards, or about two-thirds of a ton.
River rock is larger and rounder than pea gravel, so it covers a bit less area per yard. For a decorative bed, 2 inches is plenty. For a dry river bed that carries real water, go 3 to 4 inches so the rock stays put during a storm.
They look similar but do different jobs. River rock is larger (1 to 3 inches), smoother and heavier — best for dry creek beds, drainage swales and decorative borders. Pea gravel is smaller (about 3/8 inch) and shifts underfoot — better for paths and patios where you walk. See the pea gravel calculator if you need a walking surface.
A cubic yard of river rock weighs about 1.4 tons, or 2,800 pounds. Larger rock weighs slightly more, smaller rock slightly less.
Two inches for a decorative bed, and 3 to 4 inches for a dry river bed or drainage swale that carries water.
At 2 inches deep, a 10 by 10 foot area needs about 0.62 cubic yards, or 0.87 tons of river rock.
Yes. Lay landscape fabric first so the rock does not sink into the soil and weeds do not come up through it.
Yes. The gaps between the larger stones let water flow through fast, which is why river rock is used for dry creek beds and French drains.