Gravel Calculator

How Much Gravel Do I Need?

Gravel is sold by the ton for bulk deliveries and by the bag at retail stores. The tricky part is that most people think in terms of area and depth — square feet and inches — while suppliers think in cubic yards or tons. This calculator bridges that gap, but understanding the conversion helps you verify quotes and catch errors in contractor estimates.

The base formula is straightforward: length × width × depth (all in feet) gives you cubic feet. Divide by 27 to convert to cubic yards. To get tons, multiply cubic yards by the material density — most gravel weighs approximately 1.35 tons per cubic yard, though this varies from 1.1 for lightweight lava rock to 1.5 for dense crusher run. A 10 × 20 foot area at 3 inches deep needs about 1.85 cubic yards or roughly 2.5 tons of standard crushed gravel.

Depth Guidelines That Actually Work

The depth you need depends entirely on what the gravel is doing. Decorative ground cover in a flower bed needs just 2 inches — enough to suppress weeds and look clean. A patio base or walkway foundation needs 3-4 inches of compacted base material with a separate layer of surface gravel. Driveways need the most: 4-6 inches of compacted crusher run base topped with 2-3 inches of finish gravel, for a total depth of 6-9 inches. Skimping on driveway depth is a false economy — thin gravel on soft subgrade means ruts and mud within one season.

An important distinction that trips up first-time buyers: you need to order more than the calculated volume because gravel compacts. Loose gravel settles 20-30% when compacted with a plate compactor or under vehicle traffic. If your calculation says 3 tons, order 3.5-4 tons. Running short and needing a second delivery almost always costs more than slightly over-ordering, because delivery fees are per trip regardless of quantity.

Gravel Types and Where to Use Each

Crushed stone (#57 or #67) is the workhorse — angular edges lock together and compact well, making it ideal for driveways, paths, and base layers. The numbers refer to stone size: #57 is roughly 1 inch, #67 is three-quarter inch. Pea gravel is smooth and round, pleasant to walk on barefoot but terrible for driveways because it never locks together — tires push it into ruts. Use pea gravel for garden paths, around fire pits, and between stepping stones.

Crusher run (also called processed gravel or road base) is the best material for anything that needs to be solid and stable. It contains a mix of crushed stone and fine particles (stone dust) that pack together into an almost concrete-like surface when compacted wet. Every gravel driveway should start with a base of crusher run. Decorative river rock is the most expensive option and purely aesthetic — beautiful around landscaping but impractical for surfaces that need stability.

Delivery vs Pickup: The Real Math

Bulk gravel from a quarry or landscape supply yard costs $25-65 per ton depending on type and region. Delivery adds $50-150 per trip. Bagged gravel at a home center costs $4-8 per 50-pound bag, which works out to $160-320 per ton — three to five times the bulk price. The breakeven point is typically around 1-2 tons: below that, bags from a home center are more convenient despite the premium. Above that, bulk delivery saves substantial money. A standard dump truck load is 10-15 tons, so most residential projects fall well within one delivery.

How many tons of gravel per cubic yard?

Standard crushed gravel: approximately 1.35 tons per cubic yard. Pea gravel: 1.25 tons. Crusher run: 1.45 tons. River rock: 1.1 tons. Always confirm with your specific supplier as density varies by quarry and moisture content.

How thick should gravel be for a driveway?

6-9 inches total: 4-6 inches of compacted crusher run base plus 2-3 inches of surface gravel. Compact each layer separately with a plate compactor. Thinner installations will develop ruts and potholes within 1-2 seasons, especially in areas with freeze-thaw cycles.

How much does a load of gravel cost?

Bulk crushed stone: $25-65 per ton + $50-150 delivery. A typical driveway project needs 10-20 tons, costing $400-1,500 for materials and delivery. Compare this to bags at a home center: the same quantity would cost $1,600-6,400. Bulk is always cheaper for more than 1-2 tons.

Do I need landscape fabric under gravel?

For decorative areas and garden paths: yes, fabric prevents gravel from sinking into soil and weeds from growing through. For driveways and structural bases: usually no — fabric can actually reduce stability by preventing the base material from locking into the subgrade. Use geotextile fabric only when recommended by your specific application.