Rock Calculator - Calculate Cubic Yards and Tons Needed

Calculate how much landscaping rock or decorative stone you need for your project with our free rock calculator. Get instant results in cubic yards, cubic feet, and cubic meters.

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Volume needed:
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Tip: For decorative landscaping, 2-3 inches is typical. For drainage projects, 3-6 inches works best.

How Much Rock Do I Need?

The amount of rock you need depends on: 1. Rock size - Larger rocks cover more area at the same depth 2. Project type - Decorative, drainage, erosion control, or pathways 3. Depth desired - Varies by rock type and purpose

How to Use the Rock Calculator

This calculator offers two convenient methods to calculate your rock needs:

Option 1: By Dimensions

Enter the length, width, and desired depth of your rock area. Perfect for garden beds, pathways, or water features.

Option 2: By Area

If you already know the square footage of your area, simply enter that value along with your desired rock depth.

Recommended Rock Depth by Type and Purpose

Different projects and rock sizes require different depths:

By Rock Size: - Pea gravel (1/4"-1/2"): 2-3 inches - Small river rock (1"-2"): 2-3 inches - Medium river rock (2"-4"): 3-4 inches - Large river rock (4"-8"): 4-6 inches - Boulders (8"+): Individual placement

By Purpose: - Decorative landscaping: 2-4 inches - Weed suppression: 3-4 inches minimum - Drainage systems: 3-6 inches - French drains: 6-12 inches - Erosion control: 4-6 inches - Dry creek beds: 4-8 inches - Pathways: 2-4 inches

Understanding Rock Measurements

Cubic Yards

Landscape rock is typically ordered by the cubic yard. One cubic yard covers: - 324 square feet at 1 inch depth - 162 square feet at 2 inches depth - 108 square feet at 3 inches depth - 81 square feet at 4 inches depth

Tons

Rocks are often sold by weight (tons). As a general rule: - Small rock/pea gravel: ~1.3 tons per cubic yard - River rock: ~1.2-1.4 tons per cubic yard - Lava rock: ~0.5-0.7 tons per cubic yard (very light!) - Crushed stone: ~1.4-1.5 tons per cubic yard - Limestone: ~1.3 tons per cubic yard - Granite: ~1.4 tons per cubic yard

Types of Landscape Rock

Common rock types for landscaping:

1. River Rock

  • Sizes: 1"-8" (smooth, rounded)
  • Best for: Decorative beds, water features, dry creek beds
  • Pros: Natural appearance, smooth edges, won't degrade
  • Colors: Gray, tan, brown, mixed earth tones
  • Cost: Moderate to high

2. Pea Gravel

  • Size: 1/4"-1/2" (small, rounded)
  • Best for: Pathways, patios, playgrounds, drainage
  • Pros: Comfortable to walk on, good drainage, affordable
  • Colors: Tan, white, brown, mixed
  • Cost: Low to moderate

3. Lava Rock

  • Sizes: 1/2"-3" (porous, lightweight)
  • Best for: Decorative mulch, drainage, tropical landscaping
  • Pros: Very lightweight, retains moisture, natural red/black color
  • Colors: Red, black
  • Cost: Moderate to high

4. Mexican Beach Pebbles

  • Sizes: 1"-3" (smooth, flat)
  • Best for: High-end landscaping, modern design, water features
  • Pros: Elegant appearance, smooth texture
  • Colors: Black, white, gray
  • Cost: High

5. Crushed Granite

  • Sizes: 1/4"-3/4" (angular fragments)
  • Best for: Pathways, decomposed granite surfaces, xeriscape
  • Pros: Compacts well, natural look, affordable
  • Colors: Gray, tan, pink
  • Cost: Low to moderate

6. Marble Chips

  • Sizes: 1/2"-1" (angular, bright)
  • Best for: Decorative accents, modern landscapes, path edging
  • Pros: Bright white color, reflects light
  • Colors: Pure white, pink
  • Cost: Moderate to high

7. Slate Chips

  • Sizes: 1/2"-3" (flat, angular)
  • Best for: Contemporary landscapes, mulch alternative
  • Pros: Unique flat shape, rich colors
  • Colors: Gray, purple, red
  • Cost: Moderate to high

Landscape Rock Installation Guide

Proper Installation Steps:

  1. Mark area and measure accurately
  2. Remove vegetation and debris
  3. Level and grade for proper drainage
  4. Install edging (metal, plastic, or stone borders)
  5. Lay landscape fabric (essential for weed prevention)
  6. Spread rocks evenly to desired depth
  7. Rake and level surface
  8. Optional: Apply stabilizer for pathways

Landscape Fabric: Why It's Important

  • Prevents weeds from growing through
  • Keeps rocks from sinking into soil
  • Maintains clean appearance
  • Extends life of rock installation
  • Use commercial-grade (not thin plastic sheeting)

Buying Landscape Rock: What You Need to Know

Bulk vs. Bagged

  • Bulk rock (by the ton or cubic yard): Most economical for areas over 50 square feet
  • Bagged rock: Better for small accent areas, easier to transport

Cost Factors

  • Rock type: Specialty rocks (lava, Mexican pebbles) cost significantly more
  • Size: Larger individual rocks often cost more per ton
  • Color: Rare or imported colors increase price
  • Delivery: Typically $50-150 depending on distance
  • Quantity: Bulk orders have better per-unit pricing

Ordering Tips

  1. Order 10-15% extra for settling and gaps
  2. View samples in person (photos can be misleading)
  3. Confirm delivery truck access
  4. Consider color contrast with your home/landscaping
  5. Check reviews for color consistency
  6. Ask about minimum order requirements

Landscape Rock Design Tips

Color Selection:

  • Light rocks (white, tan): Make spaces feel larger, reflect heat
  • Dark rocks (black, charcoal): Create dramatic contrast, absorb heat
  • Earth tones (brown, rust): Natural, blend with surroundings
  • Multi-color: More forgiving, hides debris better

Size Selection:

  • Large areas: Use larger rocks (less expensive, easier to install)
  • Small spaces: Smaller rocks look better proportionally
  • Around plants: Match rock size to plant size
  • Pathways: Pea gravel or small river rock for comfort

Design Principles:

  • Use odd numbers of boulders for focal points
  • Layer different sizes for depth
  • Create dry creek beds with graduated sizes
  • Mix textures for visual interest
  • Leave space around plant stems for growth

Common Rock Landscaping Mistakes

  1. No landscape fabric: Weeds grow through, rocks sink into soil
  2. Insufficient depth: Looks sparse, soil shows through
  3. Wrong size for application: Large rocks uncomfortable on paths
  4. Poor drainage planning: Water pools, rocks shift
  5. No edging: Rocks spread into lawn and beds
  6. Ordering too little: Color/size may not match if reordering
  7. Not considering maintenance: Light rocks show dirt easily

Landscape Rock Maintenance

Regular Care:

  • Rake occasionally to maintain even appearance
  • Remove debris and leaves (leaf blower works great)
  • Top up rocks every 2-3 years as they settle
  • Spot weed control for any breakthrough weeds
  • Rinse light-colored rocks annually with hose

Long-term:

  • Rock landscapes are very low maintenance
  • Doesn't decompose like mulch
  • Color won't fade (quality rock)
  • Lasts indefinitely with proper installation

Benefits of Landscape Rock

  • Low maintenance: Doesn't need annual replacement like mulch
  • Weed suppression: With fabric, minimal weeds
  • Water conservation: Reduces evaporation
  • Fire resistance: Safer in wildfire-prone areas
  • No decomposition: Doesn't attract pests or rot
  • Erosion control: Holds soil in place
  • Clean appearance: Modern, tidy look
  • Versatile: Works with many design styles

Landscape Rock vs. Mulch

Rock Advantages:

  • Never needs replacement
  • Doesn't blow away in wind
  • No annual cost
  • Fire resistant
  • Stays in place

Mulch Advantages:

  • Improves soil as it decomposes
  • Better insulation for plant roots
  • More natural for traditional gardens
  • Easier to change design
  • Lower initial cost

Best Use:

  • Rock: Modern landscapes, arid climates, low-maintenance areas
  • Mulch: Garden beds with frequent planting changes, traditional styles

Frequently Asked Questions

How much rock do I need to cover 100 square feet?

At 3 inches deep, you need about 1 cubic yard (1.3-1.4 tons depending on rock type).

What's the cheapest landscape rock?

Pea gravel and crushed granite are typically the most affordable options at $30-50 per cubic yard.

Does landscape rock attract snakes?

Rock can provide shelter for snakes in some regions. Use fine gravel or small river rock and keep landscape fabric intact to minimize this.

How deep should rock be to prevent weeds?

With landscape fabric, 2-3 inches is sufficient. Without fabric, 4+ inches is recommended (though weeds may still appear).

Can I put landscape rock directly on soil?

You can, but landscape fabric is strongly recommended to prevent sinking and weed growth.

How long does landscape rock last?

Indefinitely! Natural stone doesn't degrade. You may need to add more over time as rocks settle or shift.

What size rock is best for around a house?

1-2 inch river rock or pea gravel works well. Larger rocks (3-6 inches) can be used for accent areas.

Can I use landscape rock in a vegetable garden?

Not recommended. Mulch is better for vegetable gardens as it adds nutrients to soil and is easier to work with when planting.

Related Calculators

Looking for other landscaping calculations? Check out our: - Gravel Calculator - Mulch Calculator - Topsoil Calculator - Sand Calculator

Pro Tip: Visit a landscape supply yard in person to see actual rock before ordering. Colors and sizes can look very different in photos than in real life!