How Much River Rock Do I Need?
Calculate the exact amount of river rock or landscape stone for your project. Get results in cubic yards and tons with cost estimates for beds, dry creek beds, and drainage areas.
Quick Answer
A 100 sq ft landscape bed at 3 inches deep needs about 0.93 cubic yards (~1.25 tons) of river rock. A dry creek bed 2 ft wide × 20 ft long at 4 inches deep needs about 0.49 cubic yards (~0.67 tons).
Enter your dimensions above to calculate river rock needed.
💡 1 cubic yard of river rock covers approximately 100 sq ft at 3 inches deep
How to Calculate River Rock Needed
Formula
Length (ft) × Width (ft) × Depth (in) ÷ 324 = Cubic Yards
Multiply your area's length by width to get square footage. Multiply by depth in inches, then divide by 324 to convert to cubic yards. Multiply cubic yards by 1.35 to get approximate tons.
Example
For a 12 ft × 20 ft landscape bed at 3 inches deep: 12 × 20 × 3 ÷ 324 = 2.22 cubic yards. At 1.35 tons per cubic yard, that's about 3 tons.
Tips & Best Practices
- •Always lay landscape fabric under river rock — it prevents weeds and keeps rock from sinking into soil.
- •Order 10% extra to allow for edge depth and any irregular sections.
- •Smaller river rock (3/4 in) works well for tight beds and paths; larger sizes (1–3 in) are better for dry creek beds and drainage.
- •For drainage use, skip the landscape fabric — you want water to flow freely through the rock.
- •River rock weighs approximately 1.35 tons per cubic yard — heavier for large cobbles.
Quick Reference
1 cubic yard of river rock covers approximately 100 sq ft at 3 inches deep
River Rock Coverage per Cubic Yard
One cubic yard of river rock covers approximately 100 square feet at 3 inches deep, or about 162 square feet at 2 inches deep.
One cubic yard equals 27 cubic feet. The table below shows how many square feet one cubic yard covers at common depths — use this as a quick reference when estimating how much river rock to order.
| Depth | Coverage per Cubic Yard | Common Use |
|---|---|---|
| 2 inches | ~162 sq ft | Paths & light decorative beds |
| 3 inches | ~100 sq ft | Landscape beds & borders |
| 4 inches | ~81 sq ft | Dry creek beds & drainage |
| 6 inches | ~54 sq ft | Erosion control & large creek beds |
River rock weighs approximately 1.35 tons per cubic yard for small to medium sizes. Large cobbles and boulders run heavier — adjust your estimate if ordering 2–5 inch rock.
Which River Rock Size to Use
Size matters more with river rock than almost any other landscape material. The right size depends on your project — not just appearance.
River rock is smooth and rounded by nature, which is why it looks great but won't compact or interlock the way crushed stone does. That's a feature in landscape beds and decorative areas — but keep it out of structural driveway applications.
Small River Rock (3/4 in)
Tight, uniform look. Best for narrow landscape beds, pathways, and around small plants. Easy to rake and reposition. ~1.35 tons per cubic yard.
Medium River Rock (1–1.5 in)
The most versatile size. Works for landscape beds, moderate drainage areas, and borders. Natural look with good coverage. ~1.35 tons per cubic yard.
Large River Rock (1–3 in)
The go-to size for dry creek beds and drainage swales. Large enough to stay in place during heavy rain, small enough to create a natural-looking stream channel. ~1.3 tons per cubic yard.
Extra Large River Rock (2–5 in)
Best for erosion control, under downspouts, and large decorative features. Stays put in high-flow areas. Use as edging stones or accent pieces in creek bed designs. ~1.25 tons per cubic yard.
Compare sizes and check bulk delivery pricing at bulk river rock — use code MEADOWLARK for 5% off.
River Rock for Common Projects
Use the estimates below as a quick reference, or run the calculator above for your exact dimensions.
Landscape Beds
Most landscape beds look best at 2–3 inches of river rock depth — enough to suppress weeds and create a clean finished look without excessive weight on plant roots. Always lay landscape fabric first.
| Bed Size | Depth | Cubic Yards | Approx. Tons |
|---|---|---|---|
| 4×10 ft (40 sq ft) | 3 in | 0.37 yd³ | ~0.5 tons |
| 10×10 ft (100 sq ft) | 3 in | 0.93 yd³ | ~1.25 tons |
| 10×20 ft (200 sq ft) | 3 in | 1.85 yd³ | ~2.5 tons |
| 20×20 ft (400 sq ft) | 3 in | 3.7 yd³ | ~5 tons |
Dry Creek Beds
Dry creek beds typically need 4–6 inches of stone depth and a mix of sizes: larger rock (1–3 in) for the channel fill, with bigger accent stones along the edges. A 2 ft wide channel is a common starting point.
| Creek Length | Width × Depth | Cubic Yards | Approx. Tons |
|---|---|---|---|
| 20 ft | 2 ft × 4 in | 0.49 yd³ | ~0.67 tons |
| 40 ft | 2 ft × 4 in | 0.99 yd³ | ~1.33 tons |
| 60 ft | 3 ft × 6 in | 3.33 yd³ | ~4.5 tons |
| 100 ft | 3 ft × 6 in | 5.56 yd³ | ~7.5 tons |
Under Downspouts & Drainage Areas
A splash pad under a downspout typically needs a 3–4 ft diameter area at 4–6 inches deep. Use larger river rock (1–3 in or 2–5 in) — it resists wash-out under heavy flow better than small stone. For French drain systems use crushed angular stone, not river rock — round stones don't compact around the pipe properly.
Paths & Walkways
River rock paths need 2–3 inches of small to medium stone (3/4 in to 1.5 in) contained by landscape edging. Without edging, rock migrates into adjacent beds within one season. Unlike crushed gravel, river rock doesn't compact — so paths feel soft underfoot, which suits some applications and frustrates others.
What to Put Under River Rock
In most landscape applications, landscape fabric under river rock is worth the extra step. In drainage applications, skip it entirely.
Landscape Beds & Decorative Areas
Use woven landscape fabric. It blocks weeds from below, prevents rock from sinking into soil over time, and is easy to cut around plants. Avoid thin plastic sheeting — it tears, blocks water from reaching roots, and creates more problems than it solves. Secure with ground staples every 12–18 inches along edges and seams.
Drainage Swales & French Drains
No landscape fabric. You need water to flow freely through the stone. For French drain trenches, use a sock-wrapped perforated pipe instead of relying on the stone alone. For erosion control swales, larger river rock (2–5 in) placed directly on prepared soil holds up well without fabric.
Dry Creek Beds
Landscape fabric under dry creek beds is debated. It helps suppress weeds and keeps the channel looking clean, but can impede drainage in heavy rain events. A common compromise: use fabric under decorative sections, skip it where the creek connects to an actual drainage path.
Before You Order
- ☐Measure your entire project area — beds are rarely perfectly rectangular; add the sections together
- ☐Choose your size before ordering — 3/4 in for beds and paths, 1–3 in for creek beds, 2–5 in for drainage and erosion
- ☐Order landscape fabric and ground staples before the rock arrives — install it first
- ☐Add 10% to your calculated amount for edges, irregular areas, and depth variation
- ☐Check dump truck access — river rock is heavy and almost always delivered by the ton in bulk
- ☐Confirm depth: 2–3 in for beds, 3–4 in for paths, 4–6 in for dry creek beds
Ordering in bulk?
For anything over a yard or two, bulk delivery by the ton is significantly cheaper than bagged stone. Check local delivery pricing for small river rock, medium, and large river rock.
Prices and availability vary by location. Use code MEADOWLARK for 5% off your first bulk order.
Frequently Asked Questions
How many cubic yards of river rock do I need?+
Use the formula: Length (ft) × Width (ft) × Depth (in) ÷ 324 = Cubic Yards. A 100 sq ft bed at 3 inches deep needs 0.93 cubic yards. A 200 sq ft bed at 3 inches needs 1.85 cubic yards. Always add 10% for edges and settling.
How much does river rock cost per ton?+
River rock costs $25–$90 per ton for bulk delivery, depending on size and type. Standard small river rock (3/4 in) starts around $27/ton. Decorative varieties (Indiana river rock, Merrimac) run $75–$175/ton. Specialty stone like Mexican beach pebbles can reach $400–$800/ton.
How deep should river rock be?+
For landscape beds and weed suppression, use 2–3 inches of river rock. For dry creek beds, 4–6 inches provides a natural look and good drainage. For paths and walkways, 2–3 inches gives comfortable footing. Always install landscape fabric underneath for beds and paths.
How many bags of river rock do I need?+
A standard 0.5 cubic foot bag covers about 2.5 sq ft at 2 inches deep. A 1 cubic foot bag covers about 5 sq ft at 2 inches deep. For anything over 50 sq ft, bulk delivery by the ton is significantly cheaper than bags — often 40–60% less.
What size river rock should I use?+
Use 3/4 in river rock for tight landscape beds, paths, and around plants. Use 1–1.5 in for general landscape beds and light drainage. Use 1–3 in for dry creek beds, decorative features, and drainage swales. Use 2–5 in for large dry creek beds, erosion control, and under downspouts.
Common River Rock Projects
River RockGuides & Resources
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