River rock calculator for Illinois

River rock coverage starts with the size of the stone. Cover the soil with a layer near twice the stone diameter: use 1-inch rock at 2 inches deep, while 3-inch material needs 4 inches or more. As a result, the same ton spreads over half the area. Choose a size and enter the bed measurements in this river rock calculator for a tonnage result based on river rock at 2,700 lb per cubic yard. The pile at delivery can seem smaller than expected because a ton amounts to only three quarters of one cubic yard. If fabric shows after the rock is spread, add depth rather than assuming the quantity was wrong.

Plan the order

1. Record the length and width of every bed or border in feet, then use multiple-areas mode to add separate sections together.
2. Use a layer about twice the rock diameter: 2 inches with 3/4 to 1 inch stone, 3 to 4 inches with 1 to 3 inch stone, and 4 to 5 inches for larger pieces.
3. For cubic yards, divide cubic feet ÷ 27; calculate tons with yards × 1.35.

Tons of coverage by size

Install fabric before rock

Without landscape fabric, stone gradually works down into the ground and weeds can emerge between the pieces. In three years, that can leave a bed needing more rock, despite fabric costing only a few dollars a roll. Install non-woven fabric, hold it with pins, and place the stone over it. For drain rock in an active drainage route, fold the fabric around the stone rather than placing it below.

Natural-looking rock bed details

• Use two sizes together: lay a 1-2 inch base, then place larger stones in small groups. Material all in one size can look like a parking lot median.
• Set the largest anchor rocks in a dry creek bed one third below grade so the arrangement appears shaped by water.
• Once the rock is in place, rinse it. Quarry dust on delivered stone can mute the color until a hose-down removes it.
• At foundations, install 3 to 4 inches of rock over fabric and slope the surface slightly away from the wall. This creates a clean border while directing roof water along it.
• Use a blower at a low setting to remove leaves. A rake can throw rock into the grass, where mower blades may hit it later.

Example: a 200-square-foot bed

For one-inch river rock at 2 inches deep: 200 x 0.167 = 33 cubic feet = 1.2 cubic yards, or about 1.7 tons. Order two tons. Use the extra to deepen the front edge, the area people notice first and where coverage thins sooner.

Rock or mulch over five years

Mulch costs less for each delivery and adds organic matter, but it needs replacing every year or two. River rock has a higher initial cost and usually keeps a similar appearance into year five. Since rock heats nearby soil during summer, mulch generally suits planted beds, while rock works well at borders, drainage lines, and edges. Enter matching dimensions in both calculators to see how the tonnage creates the price difference.

River rock coverage and pricing FAQs

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