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Crushed Stone vs. Pea Gravel vs. River Rock

Not all gravel is created equal. Choosing the wrong type for your project will lead to drainage issues, shifting pavers, or a driveway that looks like a mess.

• Crushed Stone (Crusher Run / 3/4" Minus): The absolute best choice for structural bases (driveways, patios, under pavers). It has jagged edges that lock together when compacted, creating a solid, concrete-like foundation that doesn't shift.
• Pea Gravel: Small, smooth, round stones. Great for drainage (French drains), dog runs, and decorative pathways. Never use pea gravel as a base for pavers or concrete; the round stones will roll and shift under weight, causing your patio to sink.
• River Rock: Larger, smooth, decorative stones. Used for landscaping, dry creek beds, and erosion control. It is heavy and expensive, so it is rarely used for structural bases.

The "Compaction" Secret (Why You Need Extra)

If you order exactly 10 cubic yards of gravel to fill a 10-cubic-yard hole, you will come up short. Why? Because gravel is full of air gaps. When you drive a plate compactor or a heavy roller over it, those air gaps are crushed out, and the gravel level drops by 15-20%.

Tons vs. Cubic Yards: Don't Get Ripped Off

Landscape supply yards sell gravel by the ton (weight), but you measure your project in cubic yards (volume). The conversion depends entirely on the density of the rock.

• Crushed Stone: 1 cubic yard weighs about 1.35 tons.
• Pea Gravel: 1 cubic yard weighs about 1.30 tons (slightly lighter due to round shape).
• River Rock: 1 cubic yard weighs about 1.50 tons (much denser).

If a supplier quotes you a price per cubic yard, make sure you know the weight conversion so you can compare it accurately to a price per ton!

Common Project Types & Depth Guides

The required depth of your gravel base dictates how much material you need. Here are the industry standards.

• Paver Patio Base: 4 inches of compacted crushed stone. This is the standard for pedestrian traffic. If you are building in an area with heavy clay soil or harsh winters, bump it up to 6 inches.
• Gravel or Asphalt Driveway: 6 to 8 inches of compacted crushed stone. Driveways hold cars, which are incredibly heavy. A 4-inch base will crack and rut within a year under vehicle weight.
• French Drain: Use pea gravel. The trench should be 12-18 inches deep, and the perforated pipe should be completely surrounded by at least 2 inches of gravel on all sides.

Frequently Asked Questions

How much does a cubic yard of gravel weigh?

It depends on the rock type. Crushed stone weighs about 2,700 lbs (1.35 tons) per cubic yard. Pea gravel is slightly lighter at 2,600 lbs. River rock is the heaviest at 3,000 lbs per cubic yard.

Can I put gravel directly on dirt?

For a temporary path, yes. For a permanent driveway or patio, absolutely not. You must excavate 4-6 inches of topsoil first, lay down geotextile fabric to prevent weeds, and then add your gravel base. Otherwise, the gravel will sink into the mud.

What is the best gravel for a driveway?

Crushed stone (specifically "crusher run" or "3/4 inch minus"). The jagged edges lock together when compacted, creating a solid surface. Avoid round stones like pea gravel, which will shift and roll under car tires.

How do I keep gravel from spreading?

You must install edge restraints. For driveways, use heavy plastic or metal edging spiked into the ground. For pathways, use wooden or stone borders. Without edges, the gravel will slowly migrate into your lawn.

How thick should a gravel driveway be?

For a standard residential driveway, you need a 6 to 8-inch compacted base of crushed stone. If you have heavy clay soil or live in a freeze-thaw climate, go with 8 inches to prevent frost heave and rutting.

Which gravel type is cheapest for a driveway?

See our Gravel Driveway Cost Guide for a full cost comparison between crushed stone, pea gravel, and river rock, including why density alone changes your total tonnage by double digits.