How much landscaping rock do I need? Use this calculator to find exact tonnage from your area dimensions, or see how much ground your bulk rock order will cover. Accurate coverage estimates prevent costly over-ordering.
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Last updated March 31, 2026 by our expert review team
| Rock Type | 2" Depth | 3" Depth | 4" Depth |
|---|---|---|---|
| Pea Gravel (3/8") | 80 sq ft | 55 sq ft | 40 sq ft |
| Crushed Stone (3/4") | 90 sq ft | 60 sq ft | 45 sq ft |
| River Rock (1-2") | 100 sq ft | 65 sq ft | 50 sq ft |
| River Rock (2-4") | 110 sq ft | 75 sq ft | 55 sq ft |
| Lava Rock | 180 sq ft | 120 sq ft | 90 sq ft |
Ruth Wairimu
Landscape Architect
Landscape architect with 9+ years of experience, AAK member, IFLA climate activist, and founder of Bloomwell.
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Certified Cost & Estimating Professional
AACE-certified estimator working with 20+ insulation companies including the two largest franchises in America.
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How we verify our calculatorsCoverage varies dramatically by rock size. Pea gravel covers 80 sq ft per ton at 2" depth, while lava rock covers 180 sq ft per ton at the same depth.
Install commercial-grade woven landscape fabric (3 to 5 oz/sq yd) before spreading rock. The Landscaping Network's rock guide recommends overlapping seams 6 inches and pinning every 2 feet with galvanized staples.
For deliveries over 3 tons, negotiate free delivery and confirm the dump truck can access your site with 10 ft wide, 12 ft tall clearance.
For specific material estimates, use our River Rock Calculator for decorative projects or the Pea Gravel Calculator for walkable surfaces.
Bulk rock costs $25 to $75/ton vs. $300 to $600/ton equivalent in bags. Switch to bulk for any project over 100 sq ft to save 70 to 85%.
Use affordable crushed stone ($30 to $55/ton) for base layers and hidden areas. Our Stone Calculator covers 8 material types with density-adjusted tonnage estimates.
This calculator converts between area and tonnage using rock-specific density values that range from 50 lbs per cubic foot (lava rock) to 105 lbs per cubic foot (decomposed granite). The density differences are significant. They can cause a 2x variation in weight for the same volume, which directly impacts your delivery requirements and material cost. All density values are based on dry-weight industry standards; wet rock at the quarry may weigh 5-10% more.
For area-to-tonnage calculations, we multiply length by width to get square footage, then by the depth (converted from inches to feet) to get cubic feet. The cubic footage is multiplied by the rock's density to get total weight in pounds, then divided by 2,000 for tons. Your selected waste factor (5-15%) is applied last. The reverse calculation divides your available tonnage back through the density and depth to determine maximum coverage area. The 50-lb bag estimate assumes standard retail packaging used by brands like Vigoro, Pavestone, and Rain Forest.
Formula
Volume (cu ft) = Area (sq ft) x Depth (in) / 12
Tons = Volume x Density (lbs/cu ft) / 2,000 x (1 + Waste %)
Coverage = (Tons x 2,000) / (Density x Depth / 12)
How much rock per square foot?
At 2-inch depth, 12 to 15 lbs for dense stones like crushed granite, or 5 to 8 lbs for lightweight lava rock. The Concrete Network's aggregate guide provides detailed density tables.
How many sq ft does a ton cover?
80 to 120 sq ft at 2-inch depth. Lava rock covers the most at 180 sq ft/ton. Crushed stone covers about 80 sq ft. River rock falls in between.
What depth prevents weeds?
3 to 4 inches over woven landscape fabric. Anything under 2.5 inches allows enough sunlight for weed seeds to germinate.
Bulk or bagged rock?
Bulk costs $25 to $75/ton. Bags translate to $300 to $600/ton equivalent. Buy bulk for projects over 100 sq ft to save 70 to 85%.
How to calculate irregular shapes?
Break into rectangles and triangles, calculate each separately, then add together. Use 15% overage instead of 10% for curved edges.
Decorative vs functional rock?
Decorative (marble, polished river rock) costs $100 to $200/ton at 2" depth. Functional (crushed stone, DG) costs $25 to $70/ton at 3 to 6" depth.
How heavy is a cubic yard?
Lava rock: 1,350 lbs. River rock: 2,400 to 2,700 lbs. Crushed stone: 2,700 lbs. Most pickup trucks max out at 1,000 to 1,500 lbs.
Need a French drain estimate?
For drainage rock around perforated pipe, our French Drain Calculator estimates washed stone, pipe, and fabric for complete drainage systems.
Decorative depth for functional applications
A 2-inch decorative layer provides zero drainage benefit. Drainage, erosion control, and pathways require 3 to 6 inches of stone.
Buying bagged rock for large projects
Bags cost $300 to $600/ton equivalent, up to 10x bulk pricing. Switch to bulk for projects over 100 sq ft. The delivery fee pays for itself immediately.
Ignoring rock density differences
Lava rock covers 180 sq ft/ton while crushed stone covers 80 sq ft/ton at the same depth. Ordering without adjusting for density causes 50%+ errors.
Skipping landscape fabric
Decorative rock sinks into soil within 1 to 2 years without fabric. Quality woven fabric at $0.15 to $0.30/sq ft prevents a complete do-over.
Not planning for delivery truck access
A 5-ton delivery needs a dump truck with 10 ft wide, 12 ft tall clearance. Measure your access path before ordering.
No edging on all four sides
Rock migrates into lawn within months without containment. Budget $1.50 to $2.00/linear foot for steel or aluminum edging.
Area: 600 sq ft
Depth: 2.5"
Material: 3.8 tons decomposed granite
Cost: $152-$266
Full front yard conversion from grass to low-maintenance xeriscape using decomposed granite with strategic boulder accents and drought-tolerant plantings. Installed over 5 oz woven fabric with steel edging. Water bill dropped 40% in the first summer.
Area: 200 sq ft (50 ft x 4 ft)
Depth: 5" (2" gravel base + 3" river rock top)
Material: 2.5 tons total (1.2 ton crushed stone + 1.3 ton river rock)
Cost: $140-$230
Linear drainage channel along the foundation using functional crushed stone base topped with decorative river rock. Dual-purpose design handles 2 inches of rainfall per hour while looking like an intentional landscape feature.
Area: 150 sq ft
Depth: 3"
Material: 1.4 tons lava rock
Cost: $105-$210
Circular 14-foot diameter fire pit area using red lava rock for a dramatic, fire-safe ground cover. Lava rock's low density (50 lbs/cu ft) means this project required 40% fewer tons than river rock, saving $150+ on material and making DIY transport feasible in two truck loads.
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.