Rock
Decorative Rock Calculator
Calculate decorative landscape rock — cobbles, lava rock, marble chips — by area, depth, and cost.
Inputs
3/8-inch decorative rock gives a fine, uniform finish for pathways, xeriscape ground cover, and modern beds.
Live estimate
Material needed
3.09 cu yd
- Cubic yards
- 3.09 cu yd
- Tons
- 4.63 tons
- Truckloads
- 0.26
- Area
- 500 sq ft
- Cubic feet
- 83.33
You will likely need
- •3.09 cu yd — material needed
- •Schedule 1 truck load
- •Approximate delivered weight: 4.63 tons
Supplier tip
Most suppliers sell decorative rock by either the cubic yard or by weight. Confirm your supplier's preferred ordering unit before purchasing.
Weight estimates are based on industry-standard average material densities. Actual delivered weights may vary by supplier and moisture content.
Diagram
Live estimate
- Mathematical quantity
- 3 cu yd
- Voids are already priced into bulk cubic-yard rock
- Informational
- Field conditions
- Not applied
- Adjusted requirement
- 3 cu yd
- Ordering rule
- Round up to whole ton
- Suggested order
- 4 cu yd
Bulk-yard cubic yards already reflect inter-particle voids. Yardexa does not add an automatic voids allowance.
What you actually need in the field, before rounding to a supplier-friendly ordering unit.
Estimator confidence
HighCrushed and rounded rock has void space between particles, but bulk-yard cubic yards already reflect that packing. No automatic order allowance is added; consider a user-selectable edge-migration condition where borders are open.
Improve confidence: Depth should be at least 2× the largest stone dimension; edge migration on open borders is a separate consideration.
Why this behavior applies: Crushed rock has visible voids between particles, but suppliers quote and deliver by geometric cubic yard at the yard's standard packing. Adding a generic voids percentage on top would silently inflate every order. Edge migration on open borders is a separate user-selectable field condition, not a universal default.
- Finished depth — Decorative rock at less than 2 in tends to show fabric or soil after a season.
- Selected stone type and size — Density and coverage vary by product (river rock vs crushed cobble vs lava rock).
- Edge containment — Rock migrates without a hard edge; expect ongoing top-off at the border.
- Order in bulk for anything over 0.5 cubic yards — bag pricing balloons fast.
- Lay a woven landscape fabric before placing decorative rock so it doesn't sink or mix with soil.
- Ask about color consistency across pallets — dye lots vary between deliveries.
- Skipping fabric and losing expensive stone into the soil.
- Underestimating waste on cobble installations — irregular placement adds up.
- Assuming lava rock and standard rock weigh the same when planning delivery.
Smart tips
- Ordering 5–10% extra is standard on irregular layouts. Running short costs more than the excess.
- Enter your dimensions to see live material estimates.
How it's calculated
Area is derived from your shape inputs and converted to sq ft.
Depth is converted to feet; cubic feet = area × depth.
Cubic yards = cubic feet ÷ 27, then × (1 + waste %) × (1 + compaction %).
Estimated tons = cubic yards (with waste) × 1.5.
Truckloads = cubic yards (with waste) ÷ truck capacity.
Total cost = cubic yards (with waste) × price per cubic yard + delivery.
Professional guidance
When to use decorative rock
Accent beds, xeriscape gardens, fire pit borders, and low-water landscapes.
Recommended depth
2 inches for finer chips (marble, quartz), 3 inches for larger cobbles.
Pro tip
Lay landscape fabric first. Decorative stone is expensive — don't lose it to weeds and soil migration.
Common mistakes
Buying by the bag for a large bed — cost balloons fast. Anything over 0.5 cu yd is cheaper in bulk.
Material assumptions
- Decorative rock density averages 1.5 tons per cubic yard (varies by material).
- Recommended depth: 2 inches for chips, 3 inches for cobbles.
- Lava rock is lighter — closer to 0.75 tons per cubic yard.
Frequently asked questions
Related calculators
Related articles
Deeper guidance from the Learn library — sizing, depth, waste, and ordering for this material.
- River Rock Size GuideRiver rock comes in sizes from pea-sized to fist-sized. Each has a specific use. Here's the full breakdown.
- Decorative Rock Size GuideFrom granite screenings to fist-sized boulders — a professional's size chart with matched use cases and coverage rates.
- How Deep Should Decorative Rock Be?Two inches for ground cover, three for weed suppression, four to six for driveways. Depth is a durability decision, not just an aesthetic one.
- Landscape Fabric: When and How to Use ItLandscape fabric is a tool, not a magic barrier. Here's when it works, when it doesn't, and how to install it so it lasts.
These results are estimates only. Confirm quantities, compaction, waste, and delivery requirements with your supplier or project professional before ordering materials.