River Rock Calculator
How much river rock do I need? Get tons, cubic yards, and coverage by stone size — plus weight per yard — for beds, paths, creek beds, and borders.
Project Dimensions
Application preset
Garden Bed
3" typical
Around plants. Adjust depth for your site conditions.
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Enter your project dimensions
Last updated May 29, 2026 by our expert review team
River Rock Sizes & Coverage
Small (1-2")
90 sq ft/ton
Pathways, borders
$80/ton
Medium (2-4")
75 sq ft/ton
Garden beds, mulch alternative
$100/ton
Large (4-8")
60 sq ft/ton
Water features, focal points
$120/ton
Cobble (6-12")
50 sq ft/ton
Dry creek beds, edging
$150/ton
Polished (1-3")
85 sq ft/ton
Premium decorative
$180/ton
Expert Contributors
Ruth Wairimu
Landscape Architect
Landscape architect with 9+ years of experience, AAK member, IFLA climate activist, and founder of Bloomwell.
See full profileHawkin
Certified Cost & Estimating Professional
AACE-certified estimator working with 20+ insulation companies including the two largest franchises in America.
See full profileUpdated May 2026
How we verify our calculatorsRiver Rock Size & Depth Guide
How Much Does a Yard of River Rock Weigh & Cover?
A cubic yard of river rock weighs about 2,700 lb (1.35 tons). One ton covers roughly 90 sq ft at 2 inches deep for 1-inch stone — larger 2–3 inch stone covers less because of the bigger voids.
| Depth | Sq ft per ton | lb per sq ft |
|---|---|---|
| 2" deep | 90 | 22 |
| 3" deep | 60 | 33 |
| 4" deep | 45 | 44 |
For 1–2 inch river rock. Larger or angular stone covers ~10–15% less per ton. Confirm exact weight with your supplier — moisture and stone type vary.
Coverage Drops as Depth Increases
sq ft/tonA 4-inch bed uses about twice as much material as a 2-inch bed. Larger rock also covers less area per ton because more space remains between stones.
Pro Tips
Check payload before pickup. One cubic yard can weigh more than a half-ton truck should carry.
For rock-lined swales and dry creek beds, the NRCS home drainage guide recommends washed rock, a safe outlet, and non-woven geotextile beneath the rock.
Put edging in before the rock arrives. Rounded stone moves more than crushed stone.
If you already know tons and need area, use the Rock Coverage Calculator.
For small, walkable decorative stone, use the Pea Gravel Calculator.
Hose the rock after spreading. Quarry dust hides the color until it washes off.
How the Calculator Works
Start with the area and installed depth. The calculator turns that into volume, then applies the density for the rock size you picked.
- Depth matters most. A 4-inch bed uses twice as much rock as a 2-inch bed.
- Rock size changes weight. Small river rock packs tighter than large cobble.
- Fabric is separate. The add-on estimate includes 10% overlap for seams and edges.
Formula
Volume (cu ft) = Length x Width x (Depth in inches / 12)
Cubic Yards = Volume / 27
Tons = Cubic Yards x Rock Density x (1 + Waste %)
Quick Reference
- Small rock density
- 1.35 t/yd³
- Medium rock density
- 1.30 t/yd³
- Large rock density
- 1.25 t/yd³
- Delivery minimum
- 1-2 tons typical
- Bag coverage
- ~3 sq ft at 2"
Frequently Asked Questions About River Rock
How much river rock per square foot?
At 2 inches deep, plan on about 25 to 30 lb per square foot. Add 10% for edges and uneven beds.
How much does a cubic yard weigh?
Most river rock weighs 2,500 to 2,700 lb per cubic yard. Smaller stone packs tighter than large cobble.
How deep for a dry creek bed?
Use 4 to 6 inches of larger cobble over fabric. Add a compacted gravel base if the channel will carry runoff.
Do I need edging?
Usually, yes. Edging keeps rounded stone from creeping into lawn, mulch, or pavement edges.
River rock vs pea gravel?
Use river rock for decorative beds and creek features. Use pea gravel when the surface needs to be smoother underfoot.
Can I put it directly on soil?
Avoid it. River rock settles into soil and weeds fill the gaps. Use woven landscape fabric first.
How is river rock delivered?
Small jobs can use bags or pickup. Once you pass 1 to 2 tons, dump delivery is usually safer and cheaper.
Need other stone types?
Use our Stone Calculator for crushed stone, lava rock, and other aggregates.
River Rock Estimates for Common Projects
Backyard Dry Creek Bed
40x3 ft, 4" deepUse larger stone in the center and medium stone near the edges. Fabric matters here because water will move soil into the channel.
Front Yard Garden Beds
350 sq ft, 3" deepThis is a delivery job, not a pickup job. Order fabric and edging before the truck arrives.
Side Yard Pathway
20x4 ft, 3" deepMedium river rock works for a low-traffic side path. Add stepping stones if people will walk it daily.
River Rock Mistakes That Cost You Money
Skipping landscape fabric
Rock settles into bare soil. Overlap woven fabric seams by at least 6 inches.
No containment edging
Rounded stone moves. Install edging before the rock is delivered.
Ordering the exact amount
A short order means a second delivery fee. Add 10 to 15% for edges and low spots.
Wrong rock size
Small stone is easier to walk on. Large cobble is better for creek beds and focal points.
Forgetting truck access
A dump truck needs room to turn and unload. Tight access means wheelbarrow time.
Spreading too thin
One inch looks sparse fast. Use 2 inches minimum for decorative beds.
Important Disclaimer
These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.
Sources
See 20 river rock landscaping ideas
Browse the looks, then price yours here.