River rock calculator for Kansas
Coverage changes with stone size: 3-inch rock takes up twice as much depth as 1-inch rock, so a ton covers half as much ground.
Enter your project dimensions
River rock coverage depends on the stone size you select. To cover the ground, use a layer close to twice the stone diameter. That means 1-inch rock is placed 2 inches deep, while 3-inch material needs 4 inches or more. The tonnage stays the same, but the coverage area is cut in half. Enter the bed measurements and stone size in this calculator for a result based on river rock weighing 2,700 lb per cubic yard. Keep in mind that a delivered ton can look smaller than expected, since it equals only three-quarters of a cubic yard. If fabric remains visible after spreading, the layer is too shallow rather than short on material.
Order sizing
- List the length and width of every bed or border in feet. Select multiple-areas mode to add the separate spaces together.
- For 3/4 to 1 inch rock, use 2 inches of depth. Choose 3 to 4 inches for 1 to 3 inch rock. Use 4 to 5 inches when placing larger material, keeping the layer about twice the rock diameter.
- Convert cubic feet to cubic yards by dividing by 27. To estimate tons, multiply the yardage by 1.35.
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 rock
Without landscape fabric, soil gradually absorbs the rock. Stones work down into exposed soil over the seasons, while weeds come up between them. In three years, the bed may need more rock, even though a roll of fabric could have avoided that expense. Put down non-woven fabric, secure it with pins, and then add the stone. For drain rock used in an active drainage route, wrap the fabric around the rock rather than laying it beneath the stone.
Ways to give rock beds a natural look
- Combine sizes by laying a 1 to 2 inch base and grouping a few larger rocks through it. Using just one size can resemble a parking-lot median.
- For a dry creek bed, sink the largest anchor rocks one third into the ground. That gives them a water-set appearance.
- After installation, spray the rock with water. Dust from delivery can mute its color until it is rinsed away.
- At a foundation, place 3 to 4 inches over fabric and slope it gently away from the wall. This gives the edge a finished look and guides roof runoff along it.
- Clear leaves using a low blower setting. A rake can toss stones into the grass, where mower blades may hit them.
Example: a 200-square-foot bed
At 2 inches deep, 200 x 0.167 = 33 cubic feet = 1.2 cubic yards, or about 1.7 tons for one-inch river rock. Order two tons. Put the extra at the front edge, since that visible area tends to lose coverage first.
Rock and mulch over five years
Mulch costs less per delivery and adds to the soil, but you need to replenish it every year or two. River rock has a higher initial cost, then generally keeps its appearance through year five. Summer heat can warm soil around the stone, making mulch a usual choice for planted beds. Rock is commonly used at borders, drainage lines, and edges. Put the same dimensions into both calculators to see how the tonnage changes the price.
River rock cost and coverage FAQs
What is the formula for calculating river rock?
What area can 1 ton of river rock cover?
What coverage do 50 lbs of river rock provide?
What does a ton of river rock cost?
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Is landscape fabric necessary under river rock?
Is it okay to install river rock over mulch?
What is the weight of a yard of river rock?
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Plan for your rock bed
River rock, large river rock, and drain rock are available by the ton, with free delivery included.
