River rock calculator for South Dakota

River rock coverage depends on the stone size. Plan on a layer about twice the stone diameter to conceal the ground: 1-inch material needs 2 inches of depth, while 3-inch stone calls for 4 inches or more. The tonnage stays the same, but the covered area is cut in half. Use this calculator to choose a size, enter the bed measurements, and calculate tons using river rock's 2,700 lb per cubic yard. Keep the delivered pile in perspective, too. One ton is three-quarters of a cubic yard, and fabric showing after the rock is spread points to insufficient depth, not too little material.

Order sizing

1. Record each border and bed in feet. Use multiple-areas mode to add separate sections together.
2. Use a layer measuring 2 inches with 3/4-1 inch rock, 3-4 inches with 1-3 inch material, and 4-5 inches when using larger rock.
3. For cubic yards, take cubic feet ÷ 27; convert yards to tons by multiplying × 1.35.

Per-ton coverage by size

Install fabric before rock

Without landscape fabric, bare ground gradually takes in the rock. Stone settles season by season, weeds come up through it, and the bed can need more rock in three years. Put down non-woven fabric, secure it with pins, then place the stone. For drain rock in an active drainage route, fold the fabric around the rock rather than placing it beneath it.

Rock-bed details that look natural

• Blend sizes by starting with a 1-2 inch base and placing groups of larger stones through it. Using one size throughout can resemble landscaping beside a paved lot.
• For a dry creek bed, set the largest anchor rocks into the ground a third of their depth to give them a water-set appearance.
• After the rock is in place, rinse it with a hose. Quarry dust can mute its color until it is washed off.
• At foundations, place 3-4 inches of rock on fabric and grade it slightly outward from the wall. This gives the edge a finished appearance while guiding roof runoff along it.
• Use a blower on low to remove leaves. A rake can throw stones into the grass, where mower blades may hit them.

Example: a 200-square-foot bed

For a 200 square foot area, one-inch river rock installed 2 inches deep calculates as 200 x 0.167 = 33 cubic feet = 1.2 cubic yards, or about 1.7 tons. Buy two tons. Use the remaining material to build up the leading edge, where rock is most noticeable and tends to spread thin first.

Rock versus mulch over five years

Mulch improves soil and costs less for each delivery, but it needs refreshing every year or two. River rock costs more at the start and generally looks much the same in year five. It can heat nearby soil during summer, so mulch is usually better for planted beds, while rock suits borders, drainage runs, and edges. Enter the same dimensions in both calculators to compare tonnage and see the price difference directly.

River rock cost and coverage FAQs

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