Calculate river rock cubic yards, short tons, 0.5 cu ft bags, and dry creek bed cost.
Use this free River Rock Calculator to find out how many cubic yards, short tons, and 0.5 cu ft bags of river stone your planting bed, border, or dry creek swale needs. Try the default: a 10 ft × 10 ft bed (100 sq ft) at a 3-inch depth with 10% waste requires 27.50 cubic feet (1.02 cubic yards), which weighs 2,613 lbs (1.31 tons at 95 lb/ft³ EPA loose rock density) or takes 55 bags.
It takes less than 30 seconds to calculate your river rock volume, tonnage, bag count, and dry creek cost.
Select Rectangle / Bed for standard planting beds and borders, Dry Creek Swale for dished drainage channels (includes a 1.15x bank-slope contour factor), Circle / Tree Ring for round beds, or Total Area if you already know your square footage.
Type your length, width (or diameter), and rock depth in inches or feet. Follow the 2x Stone Diameter Rule: use 2 to 3 inches for small pebbles, 3 to 4 inches for 1–3 inch river rock, and 5 to 6 inches for 3–5 inch cobble.
Select your river rock size (default 1–3 in Medium River Rock at 95 lb/ft³ per U.S. EPA loose rock standard, 100 lb/ft³ for small pebbles, or 90 lb/ft³ for 3–5 in cobble) and a waste % (10% for beds or 15% for dry creek swales).
Pick your retail bag size (0.5 cu ft / ~48–50 lb default) and optionally add your local price per ton and delivery fee.
Click Calculate River Rock to see your tons, cubic yards, bags, and total cost. Copy the summary table or download the official A4 PDF takeoff sheet.
To find out how much river rock you need, multiply your bed length by width in feet to get square footage, multiply that by your target depth in feet (Depth in inches ÷ 12) to get cubic feet, and divide that by 27 to get cubic yards. Multiply your cubic yards by 1.28 to 1.35 short tons per cubic yard (2,565 to 2,700 lbs/yd³) and add 10% for settling and grading waste.
Ordering smooth river stone for planting beds, foundation drip edges, or drainage swales comes down to converting three measurements—length, width, and depth—into bulk cubic yards or short tons. Landscape supply yards sell bulk river rock by the cubic yard (27 ft³) or by the US short ton (2,000 lbs), while home improvement stores sell littler quantities in 0.5 cubic foot (~48 to 50 lb) bags.
Use these four formulas to run a field material takeoff for any rectangular bed or border:
Area (sq ft) = Length (ft) × Width (ft)
Net Volume (cu ft) = Area (sq ft) × (Depth in inches ÷ 12)
Volume in Cubic Yards (yd³) = Volume (cu ft) ÷ 27
Weight in Short Tons = (Volume in cu ft × Bulk Density in lb/ft³) ÷ 2,000
For circular tree rings or round fire pit pads, measure out the full distance across the circle (diameter D) and divide that by 2 to get the radius (r):
Circular Area (sq ft) = 3.1416 × (Diameter ÷ 2)²
For a winding dry creek bed or drainage swale with sloped sides, a flat length-times-width measurement underestimates the actual surface area along the dished channel walls. Multiply the centerline length and average top width by a 1.15 bank-slope contour factor (or 1.25 for steep V-channels):
Dry Creek Swale Volume (cu ft) = Length (ft) × Top Width (ft) × 1.15 × (Depth in inches ÷ 12)
According to the U.S. Environmental Protection Agency (EPA) Standard Volume-to-Weight Conversion Factors, loose rock averages 2,570 lbs per cubic yard (95.2 lbs per cubic foot, or 1.285 short tons per cubic yard), while rounded pebbles and large stone range from 90 to 100 lbs per cubic foot (2,430 to 2,700 lbs per cubic yard). Using a verified bulk density inside a river rock calculator stops costly under-ordering when a quarry bills by scale weight instead of loader bucket volume.
Unlike crushed angular stone that locks tightly together, water-worn river rock has smooth, rounded edges. Bigger cobbles leave wider air pockets (void space) between individual stones. Due to those air gaps, a cubic foot of 3 to 5 inch river cobble actually weighs less (about 90 lb/ft³) than a cubic foot of 3/8 to 1 inch river pebbles (100 lb/ft³).
Meanwhile, bigger stones take a deeper layer. If you spread 3-inch river rock only 2 inches deep, you get a single sparse layer of cobbles with black landscape fabric showing between every stone. Always apply the 2× Stone Diameter Depth Rule: install river rock at a minimum depth equal to at least twice the average rock diameter.
Field installation rules from University of California Agriculture and Natural Resources (UCANR) recommend laying loose landscape aggregate 2 to 4 inches deep over a prepared subgrade with non-woven geotextile fabric and rigid perimeter edging so stones cannot sink into wet clay or roll into adjacent turf. If you’re installing littler 3/8-inch stone for a foot path or patio base, compare your takeoff in our Pea Gravel Calculator.
| River Rock Size Grade | Bulk Density (lb/ft³) | Weight per Cubic Yard | Tons per Cubic Yard | Minimum Layer Depth | Best Landscaping Use |
|---|---|---|---|---|---|
| 3/8″ – 1″ Small River Pebbles | 100 lb/ft³ | 2,700 lbs/yd³ | 1.35 tons/yd³ | 2″ – 3″ | Garden paths, stepping stone joints, container mulch, French drain pipe bedding |
| 1″ – 3″ Medium River Rock | 95 lb/ft³ | 2,565 lbs/yd³ | 1.28 tons/yd³ | 3″ – 4″ | Planting beds, foundation splash strips, tree rings, xeriscape ground cover |
| 3″ – 5″ Large River Cobble | 90 lb/ft³ | 2,430 lbs/yd³ | 1.22 tons/yd³ | 5″ – 6″ | Dry creek beds, downspout splash basins, sloped bank erosion control |
| 5″ – 8″ Stream Cobble / Rip-Rap | 85 lb/ft³ | 2,295 lbs/yd³ | 1.15 tons/yd³ | 6″ – 9″ | Heavy stormwater swales, pond shorelines, culvert outlets, accent borders |
One of the most typical questions before calling a stone yard is how many square feet 1 short ton (2,000 lbs) or 1 cubic yard (27 ft³) of river rock will cover. Because 1 cubic yard of medium river rock weighs 2,565 to 2,700 lbs (1.28 to 1.35 tons), a single cubic yard covers around 28% to 35% more square footage than a single ton.
Coverage per Ton (sq ft) = (2,000 ÷ Bulk Density in lb/ft³) ÷ (Depth in inches ÷ 12)
| Layer Depth | 1 Ton Coverage (1–3″ Rock @ 95 lb/ft³) | 1 Ton Coverage (Pebbles @ 100 lb/ft³) | 1 Ton Coverage (3–5″ Cobble @ 90 lb/ft³) | 1 Cubic Yard Coverage (All Sizes) |
|---|---|---|---|---|
| 2 inches deep | 126 sq ft | 120 sq ft | 133 sq ft (too thin for 3–5″) | 162 sq ft |
| 3 inches deep (Standard Bed) | 84 sq ft | 80 sq ft | 89 sq ft | 108 sq ft |
| 4 inches deep (Weed Barrier) | 63 sq ft | 60 sq ft | 67 sq ft | 81 sq ft |
| 5 inches deep (Cobble Swale) | 51 sq ft | 48 sq ft | 53 sq ft | 65 sq ft |
| 6 inches deep (Heavy Creek) | 42 sq ft | 40 sq ft | 44 sq ft | 54 sq ft |
Use the project size lookup table below to check frequent backyard takeoffs using 1 to 3 inch medium river rock (95 lb/ft³) with a standard +10% waste and settling allowance already included:
| Project Area & Dimensions | Target Depth | Net Volume | Order Volume (+10% Waste) | Order Weight (Tons / Lbs) | 0.5 cu ft Bags (~48 lb) |
|---|---|---|---|---|---|
| 50 sq ft (e.g., 10×5 ft Entry Strip) | 3 in | 12.50 ft³ (0.46 yd³) | 13.75 ft³ (0.51 yd³) | 0.65 tons (1,306 lbs) | 28 bags |
| 100 sq ft (e.g., 10×10 ft Garden Bed) | 2 in | 16.67 ft³ (0.62 yd³) | 18.33 ft³ (0.68 yd³) | 0.87 tons (1,742 lbs) | 37 bags |
| 100 sq ft (e.g., 10×10 ft Garden Bed) | 3 in | 25.00 ft³ (0.93 yd³) | 27.50 ft³ (1.02 yd³) | 1.31 tons (2,613 lbs) | 55 bags |
| 100 sq ft (e.g., 10×10 ft Garden Bed) | 4 in | 33.33 ft³ (1.23 yd³) | 36.67 ft³ (1.36 yd³) | 1.74 tons (3,483 lbs) | 74 bags |
| 150 sq ft (e.g., 50×3 ft House Border) | 3 in | 37.50 ft³ (1.39 yd³) | 41.25 ft³ (1.53 yd³) | 1.96 tons (3,919 lbs) | 83 bags |
| 200 sq ft (e.g., 20×10 ft Xeriscape Bed) | 3 in | 50.00 ft³ (1.85 yd³) | 55.00 ft³ (2.04 yd³) | 2.61 tons (5,225 lbs) | 110 bags |
| 200 sq ft (e.g., 20×10 ft Xeriscape Bed) | 4 in | 66.67 ft³ (2.47 yd³) | 73.33 ft³ (2.72 yd³) | 3.48 tons (6,967 lbs) | 147 bags |
| 500 sq ft (e.g., 25×20 ft Front Yard) | 3 in | 125.00 ft³ (4.63 yd³) | 137.50 ft³ (5.09 yd³) | 6.53 tons (13,063 lbs) | 275 bags |
Walking through real job-site dimensions shows how stone diameter, channel slope, and waste percentages change your final quarry order. Every example below matches the exact math inside our river rock calculator.
Suppose you are replacing wood mulch in a 10 ft by 10 ft courtyard bed with 1 to 3 inch river rock at a 3-inch depth (the default setting in the river rock calculator above):
You are installing a 2.5 ft wide river rock splash border along 80 linear feet of house foundation (200 sq ft total) at a 4-inch depth for heavy weed suppression and roof runoff drainage. To measure out the steel or aluminum edging needed along the lawn perimeter first, use our Linear Feet Calculator.
You are digging a 30 ft long by 4 ft wide dished dry creek swale lined with 3 to 5 inch river cobble laid 5 inches deep. Because the channel has sloped banks, choose Dry Creek Swale (1.15× contour) and +15% waste in the river rock calculator:
You are building an 8 ft diameter decorative stone ring around an oak tree using 3/8 to 1 inch river pebbles (100 lb/ft³) at a 3-inch depth with +10% waste:
How you buy river rock has a larger impact on project budget than the stone grade itself. Type in your local per-ton quote and delivery fee inside the river rock calculator to compare bulk versus bagged pricing side by side. Buying 0.5 cu ft (~48 to 50 lb) bags at a garden center costs $5.50 to $8.50 per bag. Because it takes 40 to 42 bags to equal 1 short ton (and 54 bags to equal 1 cubic yard), bagged river rock works out to $220 to $350+ per ton.
By contrast, local landscape supply yards sell bulk river rock for $65 to $145 per short ton (or $85 to $190 per cubic yard) plus a flat dump-truck delivery fee of $75 to $160. Even after paying the delivery fee, bulk river rock becomes cheaper than retail bags as soon as your project exceeds 0.75 to 1.0 ton (30 to 40 bags). If your landscaping project also includes gushing a concrete patio pad or building a block retaining wall, pair your stone estimate with our Concrete Slab Cost Calculator and Concrete Block Calculator.
| River Rock Type / Buy Format | Usual Price per Ton | Usual Price per Cubic Yard | Installed Cost per Sq Ft (3″ Depth) | Best Order Size |
|---|---|---|---|---|
| Standard Mixed River Rock (1″–3″ Bulk) | $65 – $110 / ton | $85 – $140 / yd³ | $1.10 – $1.85 / sq ft (Mat.) | 1 ton+ planting beds & borders |
| Washed Multi-Colored River Pebbles (3/8″–1″ Bulk) | $75 – $125 / ton | $100 – $170 / yd³ | $1.25 – $2.10 / sq ft (Mat.) | Walkway borders, tree rings, French drains |
| Large River Cobble / Creek Stone (3″–8″ Bulk) | $90 – $155 / ton | $110 – $190 / yd³ | $1.75 – $3.10 / sq ft (4″–5″ depth) | Dry creek beds, drainage swales, slopes |
| Dressed Mexican Beach Pebbles (Bulk / Super Sack) | $280 – $520 / ton | $360 – $680 / yd³ | $3.80 – $6.90 / sq ft (Mat.) | High-end courtyards, modern water features |
| Bagged River Rock (0.5 cu ft / ~48 lb Retail Bag) | $220 – $350 / ton eq. | $295 – $460 / yd³ eq. | $2.75 – $4.25 / sq ft (Mat.) | Small beds under 0.75 tons (<30 bags) |
Explore more aggregate, turf, and hardscape tools in our Landscaping Calculators hub or browse our full structural and site-prep suite in Construction Calculators.
Multiply your bed length by width in feet to get square feet, multiply by depth in inches divided by 12 to get cubic feet, and divide by 27 for cubic yards. Multiply cubic yards by 1.28 tons for 1–3 inch medium river rock (95 lb/ft³) or 1.35 tons for small river pebbles (100 lb/ft³), and add 10% waste.
One US short ton (2,000 lbs) of 1 to 3 inch river rock (at 95 lb/ft?) equals 21.05 cubic feet and covers 126 sq ft at a 2-inch depth, 84 sq ft at a 3-inch depth, or 63 sq ft at a 4-inch depth.
A 10 ft × 10 ft area (100 sq ft) at a 3-inch depth requires 25.00 cubic feet (0.93 cubic yards) net, and 27.50 cubic feet (1.02 cubic yards, 1.31 tons, or 55 bags of 0.5 cu ft) with 10% waste. At a 4-inch depth with 10% waste, it takes 1.36 cubic yards (1.74 tons or 74 bags).
Covering 200 square feet at a 3-inch depth with 10% waste requires 55.00 cubic feet (2.04 cubic yards), which weighs 2.61 short tons (5,225 lbs) or takes 110 bags (0.5 cu ft each). At a 4-inch depth with 10% waste, 200 sq ft requires 2.72 cubic yards (3.48 tons or 147 bags).
Always lay river rock at least twice the stone diameter over non-woven geotextile fabric: 2 to 3 inches deep for 3/8–1 inch pebbles, 3 to 4 inches deep for 1–3 inch medium river rock, and 5 to 6 inches deep for 3–5 inch cobble.
