Rock Calculator

Landscape rock weighs 1,026–2,700 lb per cubic yard depending on the rock type. Pick the rock, then enter length, width and depth below to get yards, tons, bags and cost.

Shape
Area

Tape readings work: 10' 6", 10½. Sloped? Type the depth as 2-6. Other material? Use the cubic yard calculator.

Order Estimate

0.75 cubic yards to order

rounded up to the nearest ¼ yd³

2 in15 × 6 ft2 in deep · ▢ 1 yd (3 ft)= 0.56 yd³
Solid: exact 0.56 yd³. Dashed: what you order, 0.75 yd³ (rounded up). Person: 6 ft, for scale.
Weight
0.89–1.01 tons (loose, varies with stone size)
Bags
30 × 0.5 cu ft
Cost
$41–$60

Suppliers sell by the ¼, ½ or whole yard, often with a minimum order — round up to your supplier's step.

Details: exact volume, bags vs bulk, order sheet

Exact 0.56 yd³ · 15 ft³ · 0.42 m³

At 2 in deep, 1 yd³ covers 162 ft².

You need 0.75 cubic yards of river rock ≈ 0.89–1.01 tons (loose, varies with stone size) ≈ 30 bags of 0.5 cu ft.

Order sheet for your supplier

 
River rock weight: loose, varies with stone size (Smoky Mountain Sand & Gravel). Cost: reference range, pickup at two supply yards (OH, WA) (supplier price lists, 2026); local prices vary.
 
 
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Landscape rock weight by rock type
  
Landscape rock has no single weight per cubic yard: lava rock weighs about 43% as much as river rock, well under half.
 
 
 Landscape rock weight per cubic yard  
 Material lb per yd³ tons per yd³ Bags  
   
 River rock* 2,376–2,700 1.19–1.35 0.5 cu ft  
 Lava rock* 1,026 0.51 0.5 cu ft  
 Decomposed granite* 2,400–2,700 1.2–1.35 0.5 cu ft  
 Pea gravel* 2,600–2,700 1.3–1.35 0.5 cu ft (50 lb)  
 Crushed stone 2,600–2,700 1.3–1.35 Bulk only  
  
 
 

Weight basis: river rock loose, varies with stone size; lava rock from one 0.5 cu ft bag weight; decomposed granite loose, as sold; pea gravel loose, typical; crushed stone loose, as delivered.
* Estimate: supplier data or one source only.    Sources: Smoky Mountain Sand & Gravel; Lowe's; MRM Landscape Supply (WA); Tri-State Landscape Supply (OH); HomeGuide; Sutherland Landscape (Chico, CA); Outdoor Warehouse Supply (TX); Western Materials (Valencia, CA); Earth Stone Rock (CA/AZ); Southwest Boulder & Stone; AreA Landscape Supply (Mokena, IL); Sequoia Landscape Materials (Santa Rosa, CA); Kafka Granite; Caterpillar; Vulcan Materials; USDA-NRCS.  
 
Choose the exact rock in the calculator, because one "landscape rock" figure would be off by up to 0.84 tons per yard.
  
 
  
Rock worked example: 15 × 6 ft planting bed
  
A 15 × 6 ft planting bed at 2 in deep takes 0.75 cubic yards of rock, whatever the type; the tons change with the rock.
 
     
  1. Area15 ft × 6 ft90 ft²
  2. Volume90 ft² × 2 in ÷ 1215 ft³
  3. Cubic yards15 ft³ ÷ 270.56 yd³
  4. Ordernext ¼ yard up0.75 yd³
  5. River rock× 2,376–2,700 lb0.89–1.01 tons
  6. Lava rock× 1,026 lb0.38 tons
    7.  
 
Round stone for creek beds and borders has its own river rock calculator.
  
 
  
Landscape rock FAQ
  
 
Why does lava rock weigh less than river rock?
Lava rock weighs less because the stone is porous: about 1,026 lb per yard against 2,376–2,700 lb for river rock (estimates from bag weights and one supplier).
Is landscape rock sold by the yard or by the ton?
Landscape rock is sold both ways: supply yards list some rock per cubic yard and some per ton. Enter the volume, pick the rock type, and the calculator gives both cubic yards and tons.