Landscape Rock Calculator

Extra material covers small dips, settling, spillage, and measurements that are not perfectly square. The calculated amount remains visible so you can compare both figures.

Both are shown. “Calculated” bags cover the measured volume; “Order” bags include the 10% allowance and round partial bags up to whole bags.

Volume comes directly from your dimensions. Weight is a range because moisture, particle size, composition, and compaction change bulk density.

Excavate 2 to 4 inches of soil, remove grass and weeds, rake the ground smooth, and compact the subgrade. Install commercial-grade non-woven geotextile landscape fabric, overlapping seams by 6 inches and pinning with metal staples. Install rigid edging around borders, and spread rock evenly to the recommended depth (2 to 4 inches).

Measure the area’s length and width in feet, multiply them to get square footage, multiply by depth in feet (depth in inches ÷ 12), and divide by 27 for cubic yards. Multiply cubic yards by 1.3 for tons. For example, a 150 sq ft bed at 3 in depth requires 1.39 cubic yards (about 1.8 tons).

The best material to put under landscape rock is heavy-duty non-woven geotextile landscape fabric (4 to 6 oz). It prevents rocks from sinking into subsoil, blocks weed growth, and allows rainwater to drain freely. Avoid plastic sheeting, which prevents drainage and traps stagnant water.

Landscape rock should be spread 2 to 3 inches deep for small stones (under 1 inch), 3 to 4 inches deep for medium stones (1 to 3 inches), and 4 to 6 inches deep for larger rocks (over 3 inches). A depth of at least twice the stone diameter is required to completely conceal the underlying fabric.

Color comes from the stone itself. White and cream: marble chips and white quartz, bright but quick to show dirt and algae. Gray and charcoal: crushed granite, basalt, and slate chips, the most neutral choice. Black: black granite, basalt, and black lava rock, a strong modern contrast. Red and brown: red lava rock, red granite, and brown or tan river rock, warm but hard to pair with red brick. Tan and gold: decomposed granite and buff limestone, which blend into dry, xeriscaped yards. Lava rock is far lighter than the rest, so pick it in the calculator’s selector when you use it.

Neutral and contrasting stones complement red brick best: charcoal gray landscape rock, black granite landscape rock, slate gray, tan/buff river stone, and cream decomposed granite. Avoid red lava rock or reddish mulch stone, which clash and overwhelm red brick.

A ton of bulk landscape rock costs $40 to $90 for standard crushed stone, gravel, and decomposed granite, $75 to $150 for river rock, and $150 to $300+ for premium stone such as white marble chips, lava rock, or black granite, plus delivery. Bagged rock runs $4 to $9 per 50 lb bag ($160 to $360 per ton). Installed with fabric and edging, a rock bed typically costs $4 to $12 per square foot.

Use a leaf blower on low power to clear fallen leaves and organic debris. To clean dirt and algae, spray the stones with a garden hose or pressure washer, or apply a mild solution of white vinegar and water or eco-friendly oxygen bleach to restore brightness.

White houses pair well with nearly any stone color: black granite landscape rock and dark charcoal slate create striking modern contrast, while white marble chips provide a crisp monochromatic aesthetic, and mixed tan river rock offers warm, rustic charm.

Measure the length and width of each bed section in feet to find total square feet. Decide on thickness in inches (usually 2 to 3 inches). Enter these values into the calculator above to get exact cubic yards, tons, and bag counts.

The best rock depends on the application: river rock and smooth pebbles are best for flower beds and drip edges; decomposed granite and pea gravel are best for walkways and patios; crushed limestone is best for driveways and structural base; and black granite or white marble chips are best for modern decorative accents.

Crushed gravel, #57 crushed limestone, and decomposed granite are the most affordable landscape stones, costing $30 to $50 per ton ($40 to $65 per cubic yard) in bulk from local quarries.

You can create artificial landscape rocks and boulders using hypertufa (a mixture of Portland cement, peat moss, and perlite) molded over wire mesh or cardboard forms, or by casting cement over sand molds and staining with iron oxide pigments.

River rock (1–3 inch) and pea gravel are the two most popular landscape rocks nationwide due to their smooth, natural appearance, versatile earth tones, and superior drainage capabilities.

Landscape rock glue (rock binder) is a water-permeable polyurethane or resin adhesive sprayed over clean pea gravel or small decorative stones. It locks loose pebbles into a firm, bonded crust that stops stone scatter from foot traffic and leaf blowers while maintaining water drainage.

One cubic yard of typical landscape rock weighs between 2,400 and 2,800 pounds (1.2 to 1.4 tons). Lightweight volcanic lava rock weighs only 800 to 1,400 lb/yd³, while dense decomposed granite weighs 2,500 to 2,900 lb/yd³.

A cubic yard contains 27 cubic feet. Because retail bags contain 0.5 cubic feet (approx. 50 lb), it takes 54 bags of landscape rock to make one cubic yard.