River rock calculator for Idaho

Coverage per ton depends on stone size. A ton of 3-inch rock spreads across only half the area covered by a ton of 1-inch rock.

Enter your project dimensions

Length (feet)

Enter a length greater than 0

Width (feet)

Enter a width greater than 0

Diameter (feet)

Enter a diameter greater than 0

Depth (inches)

Enter a depth between 0.25 and 24 inches

Material

Add 5% extra for compaction & spillage

River rock coverage depends on the stone size. To cover the ground, use a layer near twice the stone diameter: 1-inch material is placed 2 inches deep, while 3-inch material takes 4 inches or more. That means the same ton covers half the area. Select the size and enter the bed dimensions in this calculator for a river rock estimate based on 2,700 lb per cubic yard. Keep in mind that a ton is only three-quarters of a cubic yard, so the delivered pile may appear smaller than expected. Fabric showing after the rock is spread usually means the layer is too shallow.

Order sizing

Enter every bed or border measurement in feet. Multiple-areas mode combines the totals from separate sections.
Use a layer about twice as deep as the stone: 2 inches for 3/4 to 1 inch rock, 3 to 4 inches for 1 to 3 inch rock, and 4 to 5 inches for larger pieces.
To find cubic yards, take cubic feet ÷ 27; calculate tons with yards × 1.35.

Tons = (Area sq ft × Depth in ÷ 12) ÷ 27 × 1.35

Per-ton coverage by size

Stone size	Layer depth	1 ton covers
3/4–1" river rock	2 inches	≈ 120 sq ft
1–3" river rock	3 inches	≈ 80 sq ft
Large river rock (2–4")	4–5 inches	≈ 53 sq ft
Oversize accents	single layer	35–50 sq ft

Project	Typical size	Depth	Volume	Weight
Foundation border	40 x 3 ft	3"	1.1 yd³	1.5 tons
Dry creek bed	25 x 4 ft	4"	1.2 yd³	1.7 tons
Accent beds	≈ 150 sq ft	2"	0.9 yd³	1.3 tons
Downspout splash zones, x4	3 x 2 ft each	3"	0.2 yd³	0.3 tons
Front-yard xeriscape	≈ 600 sq ft	3"	5.6 yd³	7.5 tons

Place fabric before rock

Start with non-woven fabric, hold it down with pins, and add the rock afterward. Without fabric, bare ground lets stone settle season by season and weeds emerge, so the bed may need more rock in three years. For drain rock in an active drainage route, enclose the stone with fabric rather than placing fabric beneath it.

Ways to create natural-looking rock beds

Pair a 1 to 2 inch rock base with grouped larger stones. Using the same size throughout can make the area resemble a parking lot median.
For a dry creek bed, sink the largest anchor stones one third of their depth into the ground so the layout resembles water placement.
After installation, rinse the rock with a hose. Quarry dust can mute the color until it washes off.
At a foundation, install 3 to 4 inches over fabric and grade it gently away from the wall. This gives the edge a finished look while guiding roof water along it.
Use a low blower setting to remove leaves. A rake can send rocks into the grass, where mower blades may strike them later.

Example: a 200-square-foot bed

For one-inch river rock installed 2 inches deep, the calculation is 200 x 0.167 = 33 cubic feet = 1.2 cubic yards, or about 1.7 tons. Buy two tons. Place the extra along the front edge for added depth, since that area is most visible and usually thins before the rest.

Rock versus mulch over five years

Mulch adds organic matter to soil and has a lower delivery cost, but it needs replacing every year or two. River rock has a higher initial cost and generally looks much the same in year five. Rock can heat nearby soil during summer, so mulch is often used around plantings, while rock works well for edges and water-routing areas. Enter matching measurements in both calculators to see how the tonnage accounts for the price difference.

River rock coverage and pricing questions

How can I figure out the river rock quantity I need?

For tons, first multiply the bed's square feet by its depth in feet. Divide that result by 27 for cubic yards, then multiply by 1.35. Choose a depth near twice the stone diameter.

What area can 1 ton of river rock cover?

Small stone installed 2 inches deep covers around 120 square feet per ton. At 3 inches, coverage is 80, while large rock at the needed depth reaches near 53.

What coverage will 50 lbs of river rock provide?

At a 2-inch layer, expect about 2 square feet of coverage. Bags are useful for small repairs, but larger beds call for bulk material. A 200-square-foot bed works out to about seventy 50-lb bags.

What is the price of a ton of river rock?

Decorative rock is priced above construction stone. The current per-ton price, including delivery, is listed on our River Rock product page. Four yards, a typical front-yard amount, works out to about 5.4 tons.

What depth is right for river rock?

Set the layer at twice the stone diameter: 2 inches for 3/4 to 1 inch stone, 3 inches for 1 to 3 inch material, and 4 to 5 inches for 2 to 4 inch rock. A shallow layer may leave fabric or soil exposed.

Is landscape fabric necessary beneath river rock?

Use non-woven fabric unless the rock serves an active drainage function. In that case, the fabric should surround the stone. Fabric helps limit settling and weeds growing through the gaps over time.

Can river rock be installed over mulch?

Remove the mulch before placing rock. As mulch decomposes beneath the stones, the rock can settle unevenly and the remaining material becomes compost that supports weeds.

What is the weight of a yard of river rock?

One cubic yard is about 2,700 lb, or 1.35 tons. A delivered ton creates a pile nearing three quarters of one cubic yard, often less material than expected.

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River rock, large river rock, and drain rock sold by the ton, with delivery included.

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