River rock calculator for Minnesota
Stone size changes coverage, so a ton of 3-inch rock covers half as much as a ton of 1-inch rock.
Enter your project dimensions
River rock coverage depends on the stone size. Plan a layer about twice the stone diameter so the ground stays covered. Use 2 inches of depth for 1-inch rock, while 3-inch rock calls for 4 inches or more. The tonnage stays the same, but the coverage area is cut in half. This calculator does the math: choose a size, enter your bed dimensions, and receive a ton estimate based on river rock weighing 2,700 lb per cubic yard. The delivered pile may appear smaller than expected. One ton is only three-fourths of a cubic yard. If fabric shows after spreading, the layer is too shallow rather than short on material.
Planning your order
- Use feet to enter the size of each bed or border. Multiple-areas mode combines the totals from individual sections.
- Make the rock layer twice as deep as the pieces are wide. Use 2 inches with 3/4 to 1 inch rock, 3 to 4 inches with 1 to 3 inch rock, and 4 to 5 inches for larger rock.
- Divide cubic feet by 27 for cubic yards, then multiply yards by 1.35 for tons.
Per-ton coverage by stone 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 the rock
Start with non-woven fabric, hold it in place with pins, and add the stone over it. Without fabric, bare soil takes in some rock each season, weeds can push up, and the bed may need more material after three years. For drain rock used in an active drainage route, enclose the stone in fabric rather than placing fabric below it.
Ways to give rock beds a natural look
- Start with a 1 to 2 inch layer, then group larger stones through it. One stone size can look like a parking lot median.
- Set the largest dry-creek stones one third into the soil. They will appear as though water left them there.
- Once the rock is in place, rinse it with a hose. Quarry dust can leave the color looking gray until it washes away.
- For a foundation border, lay 3 to 4 inches of rock over fabric and grade it slightly outward from the house. This creates a neat border while directing roof runoff along the surface.
- Clear leaves using a low-speed blower. Raking can send rock into the grass for mower blades to strike later.
Example calculation for a 200-square-foot bed
For 1-inch river rock spread 2 inches deep, 200 x 0.167 = 33 cubic feet = 1.2 cubic yards, or about 1.7 tons. Purchase two tons. Use the extra material to build up the front border, where coverage is most visible and tends to wear thin sooner.
Rock versus mulch over five years
River rock holds its appearance into year five, while mulch improves the soil but usually needs refreshing every year or two. Rock costs more initially and can heat the nearby soil during summer, so mulch generally belongs in planted beds. Use rock for edging, borders, and drainage lines. Enter matching dimensions in both calculators to compare the tonnage and resulting price difference.
River rock coverage and pricing questions
How can I figure out the river rock I need?
What area will 1 ton of river rock cover?
What coverage do 50 lbs of river rock provide?
What does a ton of river rock cost?
What depth is right for river rock?
Is landscape fabric necessary under river rock?
Can river rock be installed over mulch?
What is the weight of a yard of river rock?
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Buy river rock, large river rock, and drain rock by the ton with free delivery included.
