River rock calculator for North Dakota
Coverage per ton depends on rock size: 3-inch material covers half the area of 1-inch material.
Enter your project dimensions
River rock coverage is determined by stone size. To cover the ground, plan a layer near twice the stone diameter: 1-inch rock is placed 2 inches deep, while 3-inch rock calls for 4 inches or more. The tonnage stays the same, but the covered area is cut in half. Enter the bed dimensions and size in this calculator for a result based on river rock at 2,700 lb per cubic yard. The delivered pile can also appear smaller than expected. One ton is three-quarters of a cubic yard, and fabric showing after a bed is spread indicates inadequate depth rather than insufficient quantity.
Calculating your order
- Record each border or bed in feet, then combine distinct spaces with multiple-areas mode.
- Choose the layer by rock size: 2 inches for 3/4 to 1 inch material, 3 to 4 inches for 1 to 3 inch material, and 4 to 5 inches for larger rock.
- Divide cubic feet by 27 to find cubic yards, then multiply the yards by 1.35 to calculate tons.
Tons of 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 |
Install fabric before rock
Bare ground gradually absorbs stone when fabric is omitted. Rock settles a little with each season, weeds emerge through the gaps, and after three years the bed can require more material. Install non-woven fabric first, hold it with pins, and spread the rock over it. For drain rock in a working drainage path, enclose the stone with fabric rather than placing fabric beneath it.
Natural-looking rock bed details
- Use a 1 to 2 inch layer as the field, placing larger stones in grouped accents. A single consistent size can resemble a parking lot median.
- For a dry creek bed, sink the largest anchor stones one third into the ground so they appear shaped by moving water.
- After the rock is spread, rinse it with a hose. Handling dust can dull the color until it is washed off.
- For a foundation border, place 3 to 4 inches on fabric and grade it gently away from the wall. The result creates a clean edge and carries roof runoff along the bed.
- Use a blower at a low setting to remove leaves. A rake can throw stones into the turf, where mower blades can hit them.
Example: a 200-square-foot bed
For 200 square feet of one-inch river rock laid 2 inches thick, calculate 200 x 0.167 = 33 cubic feet = 1.2 cubic yards, or about 1.7 tons. Order two tons. Use the extra material to build up the exposed front edge, where coverage is most visible and tends to thin out first.
Rock and mulch over five years
Mulch improves soil and has a lower delivery cost, but it needs renewal every year or two. River rock costs more initially, then generally keeps the same appearance into year five. Because rock warms nearby soil in summer, planted beds commonly use mulch, while rock suits borders, drainage lines, and edges. Enter the same dimensions in both calculators to see how the tonnage changes the price.
River rock coverage and pricing FAQ
How can I estimate the river rock I need?
What area will 1 ton of river rock cover?
What area does 50 lbs of river rock cover?
What is the cost of a ton of river rock?
What depth is needed for river rock?
Is landscape fabric needed beneath river rock?
Can river rock be installed over mulch?
What does a yard of river rock weigh?
Other calculators
Rock beds need periodic upkeep.
River rock, large river rock, and drain rock sold by the ton, with free delivery included.
