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Gravel Calculator

Calculate gravel, crushed stone, or pea gravel needed for driveways, patios, and landscaping. Get cubic yards, tons, and cost estimates.

Common gravel density is ~2,700 lb/yd³

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How to Calculate Gravel

Measure length and width in feet, choose your depth, then use: Cubic Yards = Area (sq ft) × Depth (inches) ÷ 324. This calculator converts to cubic yards and estimates weight based on material density.

Example: 20×30 Driveway

  • Area: 600 sq ft at 4 inches deep
  • Volume: 600 × 4 ÷ 324 = 7.4 cubic yards
  • Weight: 7.4 × 2,700 lbs = ~10 tons
  • Cost at $40/yard: approximately $296 for materials

Recommended Depths

  • 2-3 inches: Decorative ground cover, garden paths
  • 3-4 inches: Patios, walkways, landscape beds
  • 4-6 inches: Driveways, parking areas (use 6" for heavy vehicles)
  • 6-8 inches: Road base, heavy traffic areas, drainage beds

Choosing the Right Gravel

  • Pea gravel: Smooth, rounded, 3/8" diameter. Good for walkways, drainage, playgrounds. Doesn't compact — shifts underfoot. $30-50/yard
  • Crushed stone (#57): Angular, 3/4" to 1". Interlocks and compacts well — best for driveways and base layers. $30-45/yard
  • Crusher run (#411): Mix of crushed stone and stone dust. Compacts into a firm surface. Best sub-base for driveways and patios. $25-40/yard
  • River rock: Rounded, 1-3" decorative stones. Permanent landscaping, dry creek beds, drainage. $40-80/yard
  • Decomposed granite: Fine, sandy texture. Natural look for paths and patios. Compacts moderately. $35-55/yard

Gravel Driveway Layers

A properly built gravel driveway has three layers:

  1. Base layer (4"): Large crushed stone (#3 or #4) for drainage and stability
  2. Middle layer (4"): Medium crushed stone (#57) fills gaps in the base
  3. Top layer (2-3"): Finer stone (#8 or crusher run) creates a smooth driving surface

Compact each layer with a plate compactor or roller before adding the next.

Ordering Tips

  • Order 10-15% extra for waste, uneven terrain, and settling over time
  • Bulk delivery ($30-50/yard) is much cheaper than bags for projects over 1-2 yards
  • Delivery trucks need access — check clearance and weight limits for your driveway
  • Install landscape fabric underneath to prevent weeds. Overlap seams by 6 inches
  • Edge with metal, plastic, or stone borders to keep gravel contained

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Frequently Asked Questions

How deep should gravel be for a driveway?

A gravel driveway typically needs 4-6 inches of gravel. Use 6 inches for heavy traffic and 4 inches for light use.

How much does a cubic yard of gravel weigh?

Most gravel weighs about 2,700 lbs (1.35 tons) per cubic yard, though this varies by type and moisture content.

How much area does a ton of gravel cover?

One ton of gravel covers roughly 80 sq ft at 3 inches deep or 50 sq ft at 5 inches deep.

What is the cheapest type of gravel?

Crushed stone and pea gravel are typically the most affordable at $30-50 per cubic yard. Decorative river rock costs more.

How many cubic yards cover 100 square feet at 3 inches deep?

Use the formula: Area × Depth ÷ 324. At 3 inches deep, 100 sq ft needs 100 × 3 ÷ 324 = 0.93 cubic yards — just under one yard.

What does the number 324 in the gravel formula represent?

324 converts mixed units: 12 inches per foot multiplied by 27 cubic feet per cubic yard equals 324. Dividing by 324 turns square-feet-times-inches into cubic yards directly.

What is the difference between gravel and crushed stone?

Gravel is naturally rounded by water erosion; crushed stone is mechanically broken and has angular edges. Angular crushed stone interlocks and compacts better, making it the preferred base layer for driveways.

How do I keep gravel from spreading into the lawn?

Install metal, plastic, or stone edging along the perimeter to contain the material. Landscape fabric underneath suppresses weeds and reduces gravel migration into the soil.