Gravel Calculator

Types of Gravel and Their Uses

Gravel is a versatile material used in a wide range of landscaping and construction projects. Understanding the different types of gravel and their specific applications can help you choose the right material for your project.

Common Gravel Types

• Pea Gravel: Small, rounded stones typically 1/8" to 3/8" in size. Available in various colors, pea gravel is popular for walkways, patios, playgrounds, and decorative landscaping due to its smooth texture and attractive appearance.
• Crushed Stone: Angular, crushed rock available in various sizes from 3/8" to 4". Commonly used for driveways, drainage applications, and as a base layer for construction projects due to its excellent compaction properties.
• River Rock: Smooth, rounded stones available in sizes from 1" to 5" or larger. Often used for decorative landscaping, water features, dry creek beds, and drainage areas. Its natural, polished appearance makes it aesthetically pleasing.
• Limestone Gravel: Crushed limestone available in various sizes. It compacts well and is commonly used for driveways, pathways, and as a base material. It has a light color that reflects heat and can help neutralize acidic soils.
• Marble Chips: Crushed marble stones available in white, pink, or other colors. Used primarily for decorative purposes in landscaping, garden paths, and around water features due to their attractive appearance.
• Decomposed Granite: Granite that has weathered to a fine, gritty material. It compacts well and is used for pathways, rustic patios, and as a soil amendment. Available in various colors depending on the source material.
• Quarry Process (QP): Also known as dense grade aggregate, this mixture of stone dust and crushed stone compacts extremely well, making it ideal for driveway bases and foundation work.
• Jersey Shore Gravel: A mixture of sand and small stones, often used for drainage and as a base material in coastal areas.
• Lava Rock: Lightweight, porous volcanic rock available in red, black, or brown. Used for decorative landscaping, fire pits, and areas where weight is a concern.

Gravel Sizes and Their Applications

Gravel is typically classified by size, with different sizes suited to specific applications:

• #10 (1/8" to 3/16"): Fine gravel used for walkways, between pavers, and as a top dressing.
• #8 (3/8"): Small gravel suitable for pathways, decorative landscaping, and as a drainage layer.
• #57 (3/4" to 1"): Medium-sized gravel commonly used for driveways, drainage applications, and as a base for patios and walkways.
• #3 (1.5" to 2"): Larger gravel used for drainage ditches, French drains, and as a base layer for driveways.
• #1 (2.5" to 4"): Very large gravel used for erosion control, drainage applications, and as a base layer for heavy-duty applications.

Recommended Depths for Different Applications

The appropriate depth of gravel depends on the intended use:

• Driveways:
  • Light-duty residential: 4-6 inches of compacted gravel
  • Heavy-duty or commercial: 8-12 inches, often with multiple layers of different-sized materials
  • Base layer: 4-6 inches of #3 or #4 gravel
  • Top layer: 2-3 inches of #57 or smaller gravel
• Walkways and Paths:
  • Base layer: 2-3 inches of crushed stone or #57 gravel
  • Top layer: 1-2 inches of pea gravel, decomposed granite, or other decorative material
• Patios:
  • Base layer: 4-6 inches of compacted crushed stone
  • Leveling layer: 1 inch of stone dust or sand
  • If using gravel as the finished surface: 2-3 inches of decorative gravel
• Landscaping and Decorative Uses:
  • Around plants: 2-3 inches
  • Dry creek beds: 3-6 inches
  • Fire pit surrounds: 2-4 inches
• Drainage Applications:
  • French drains: 8-12 inches of #3 or #57 gravel
  • Drainage ditches: 4-6 inches of #3 or larger gravel
  • Around foundation drain tiles: 6-12 inches

Installation Tips

For successful gravel installation, consider these best practices:

• Site Preparation: Remove vegetation, topsoil, and debris from the area. Grade the site to ensure proper drainage away from buildings.
• Edging: Install edging (metal, plastic, stone, or timber) to contain the gravel and maintain clean borders.
• Weed Prevention: Lay landscape fabric or geotextile before adding gravel to prevent weed growth and keep the gravel from mixing with the soil below.
• Layering: For driveways and pathways, use a base layer of larger stones topped with progressively smaller gravel for better stability.
• Compaction: Compact each layer of gravel using a plate compactor or roller for improved stability and longevity, especially for driveways and walkways.
• Drainage: Ensure proper slope (at least 1-2% grade) for water runoff, particularly for driveways and pathways.
• Maintenance: Plan for periodic additions of gravel to maintain the desired depth, as material can shift, settle, or wash away over time.

Environmental Considerations

When using gravel in your landscape, consider these environmental factors:

• Permeability: Gravel allows water to percolate into the ground, reducing runoff and supporting groundwater recharge, making it an environmentally friendly alternative to concrete or asphalt.
• Heat Reflection: Light-colored gravels reflect heat, helping to reduce the urban heat island effect compared to dark pavements.
• Local Sourcing: Using locally sourced gravel reduces transportation emissions and supports local businesses.
• Dust Control: In dry areas, very fine gravel can create dust. Consider using slightly larger sizes or applying environmentally friendly dust suppressants if needed.
• Wildlife Impact: Very small gravel can be ingested by birds or other wildlife. In sensitive areas, choose appropriate sizes to minimize this risk.

Calculating Gravel Needs

Accurate calculation of gravel quantities ensures you purchase the right amount for your project:

• Area Measurement: Measure the length and width of the area to calculate square footage.
• Depth Consideration: Determine the appropriate depth based on the application.
• Volume Calculation: Multiply area by depth to find the volume in cubic feet, then divide by 27 to convert to cubic yards.
• Weight Estimation: Different types of gravel have different densities. On average, 1 cubic yard of gravel weighs about 1.4-1.7 tons.
• Ordering Extra: Consider ordering 5-10% extra to account for settling, compaction, and irregular depths.

This Gravel Calculator simplifies the process of determining how much gravel you need for your project, helping you budget appropriately and avoid over-purchasing or running short of materials.