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Landscape Rock Calculator

Calculate cubic yards, tons, and cost for river rock, limestone, rip rap, crusher run, and other landscape stone. Enter your project dimensions below.

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Rock Types Comparison

Choosing the right rock depends on your project goals, budget, and the look you want. Each type has distinct characteristics that make it suited for specific applications.

Rock Type Typical Size Best Uses Density (t/yd³) Price Range (/yd³)
River Rock 1-3" Garden beds, dry creek beds, borders 1.25 $45-80
Limestone 1-4" Driveways, walkways, retaining walls 1.50 $35-65
Rip Rap 6-24" Erosion control, shoreline stabilization 1.35 $25-50
Crusher Run Dust to 1.5" Base layer, compacted surfaces 1.50 $20-40
Road Base Dust to 2" Driveways, parking pads, foundations 1.55 $18-35
Crushed Stone 0.5-1.5" Drainage, base material, backfill 1.35 $30-55
Crushed Concrete 0.75-2" Driveways, fill, base layer 1.30 $15-30

Prices are approximate and vary by region, supplier, and quantity ordered.

How to Calculate Rock for Landscaping

Estimating rock for a landscaping project uses the same volume formula as other bulk materials. The key difference is accounting for the specific density of your chosen rock type, since heavier stones like limestone require more tonnage per cubic yard than lighter options like river rock.

The formula: Volume (cubic yards) = Length (ft) × Width (ft) × Depth (in) ÷ 324

Once you have the volume in cubic yards, convert to weight by multiplying by the rock's density factor. For instance, limestone at 1.50 tons per cubic yard weighs significantly more than river rock at 1.25 tons per cubic yard. This matters because many suppliers sell by the ton, not by the yard.

Step-by-Step Process

  1. Measure the area. Use a tape measure to determine the length and width in feet. For irregular shapes, divide the space into rectangles, calculate each one, and add the results.
  2. Decide on depth. Most decorative rock applications call for 2-3 inches. Functional applications like base layers need 4-6 inches.
  3. Apply the formula. Multiply length by width by depth (in inches) and divide by 324 to get cubic yards.
  4. Convert to tons. Multiply your cubic yards by the density of your chosen rock from the table above.
  5. Add a buffer. Order 10-15% extra to account for settling, uneven terrain, and natural waste during spreading.

If you need rock for multiple beds or areas around your property, use our calculator's "Add Another Area" feature to total everything at once.

Rock Coverage by Size

Smaller rocks provide more uniform coverage per ton because they pack together more tightly. Larger rocks leave more gaps, so you may need additional material or a thicker layer for full coverage.

Rock Size Coverage at 2" Deep (sq.ft./ton) Coverage at 3" Deep (sq.ft./ton) Coverage at 4" Deep (sq.ft./ton)
0.5-1" (small) 120 80 60
1-2" (medium) 110 75 55
2-4" (large) 100 65 50
4-8" (extra large) 80 55 40

Coverage values are estimates and vary based on rock shape and packing density. Round river rocks leave more voids than angular crushed stone.

Example: Landscape Bed — 20 × 8 ft at 3 Inches

Suppose you are installing decorative river rock in a landscape bed measuring 20 feet long by 8 feet wide, with a 3-inch layer of stone.

  1. Multiply: 20 × 8 × 3 = 480
  2. Divide by 324: 480 ÷ 324 = 1.48 cubic yards
  3. Convert to tons (river rock at 1.25 t/yd³): 1.48 × 1.25 = 1.85 tons
  4. Add 10% buffer: 1.63 cubic yards or about 2.04 tons

At an average price of $60 per cubic yard for river rock, this project would cost roughly $98 for material alone, before delivery. Compare that with crushed stone at $30-55 per cubic yard if budget is a primary concern.

Related Calculators

Frequently Asked Questions

Measure the length and width of your area in feet and decide on a depth (typically 2-4 inches for decorative rock). Use the formula: Length × Width × Depth (inches) ÷ 324 = cubic yards. Then multiply by the material density to get tons. Add 10% extra for uneven ground and waste.

At a 2-inch depth, you need about 0.008 tons per square foot of standard landscape rock. At 3 inches, that increases to about 0.012 tons per square foot. The exact figure depends on the rock type and its density. Use our calculator above for precise results.

Rip rap consists of large, angular stones (typically 6-24 inches) used for erosion control along shorelines, slopes, and drainage channels. Landscape rock is a broader category that includes decorative stones like river rock, limestone, and flagstone used primarily for aesthetic purposes in gardens, beds, and pathways.

For most decorative landscape rock, 2-3 inches is sufficient. Larger rocks (3-5 inches in diameter) can be placed in a single layer about 3-4 inches deep. For weed suppression, use landscape fabric beneath the rock and maintain at least 2 inches of coverage. Functional base layers typically need 4-6 inches. See our gravel depth guide for more detail.

Calculate Your Rock Now

Enter your project dimensions in the calculator above to get an instant estimate for cubic yards, tons, and cost. No sign-up required.

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