How much aggregate do I need for a driveway?

For a standard driveway base, a depth of 4-6 inches of crushed stone (like #57 or Recycled Concrete Aggregate) is recommended. Measure your driveway's length and width, enter the desired depth into the calculator, and select your specific stone type to get the required tonnage.

What is the weight of crushed stone per cubic yard?

Most crushed stone aggregates weigh approximately 2,500 to 2,800 lbs (or 1.25 to 1.4 tons) per cubic yard. Compacted base material (like crusher run) is denser and can weigh closer to 1.5 tons per cubic yard.

What type of aggregate should I use for drainage?

For drainage purposes (like behind retaining walls or in French drains), use 'clean' stone without fines, such as #57 stone or 3/4-inch washed gravel. This allows water to flow through freely.

How do I calculate for a circular patio or fire pit area?

Our calculator has a 'Circle' mode. Select 'Circular' as the shape, enter measuring the diameter (width across the center) of the circle and the depth of the aggregate layer. The tool will calculate the volume and weight needed.

Should I add extra for compaction?

Yes, aggregates like crusher run or base material will compress when tamped down. It is generally recommended to order 5-10% extra material to account for compaction and potential wastage.

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Aggregate Calculator

Calculate the quantity of aggregate material needed for your project. Supports rectangular driveways or circular patios with various stone and gravel types.

Rectangular Circular

Length

Width

Depth

Aggregate Type

Price (Optional)

Per Unit

Mastering Aggregate Estimation

"Aggregate" is the construction industry's catch-all term for particulate material like sand, gravel, crushed stone, slag, and recycled concrete. It is the foundation of nearly every hardscape project, from roads and driveways to patio bases and drainage systems. However, ordering aggregate is tricky because while you measure your project area in terms of volume (Length × Width × Depth in cubic yards), suppliers almost exclusively sell the material by weight (tons).

The Aggregate Calculator solves this problem by combining precise geometric volume formulas with industry-standard density data to give you exact purchase orders. Whether you are filling a circular French drain or paving a rectangular parking pad, this tool ensures you don't overspend on delivery fees or halt work due to shortages.

Choosing the Right Aggregate Type

Selecting the specific type of stone is just as important as the quantity. Construction aggregates are classified by size and "cleanliness" (presence of rock dust):

#57 Clean Stone

Best Use: Drainage.
This 3/4" to 1" stone has been washed to remove stone dust. This creates large "voids" between the rocks, allowing water to flow through freely. Essential for French drains, septic fields, and behind retaining walls.

Crusher Run (ABC / QP)

Best Use: Bases & Driveways.
A mix of roughly 3/4" stone down to fine dust (fines). The dust acts as a binder; when wet and compacted, it locks the stones together to form a concrete-like geometric solid. Perfect for paver bases and gravel driveways.

Pea Gravel

Best Use: Walkways & Decor.
Small, rounded 3/8" stones. They don't compact well (they roll like marbles), making them poor for driveways but excellent for comfortable walking paths, playgrounds, and decorative flower beds.

Recycled Concrete

Best Use: Eco-Friendly Base.
Old concrete crushed to size. It's cheaper and lighter than virgin limestone but works excellently as a sub-base for patios and driveways.

The "Compaction Factor"

Pro Tip: Most aggregates (especially those with fines like Crusher Run) will shrink by 15-20% when mechanically compacted.
If your project calls for a 6-inch base, you likely need to spread ~7.5 inches of loose material to achieve that final depth after tamping. Always add a margin of error to your order!

Frequently Asked Questions

How thick should my gravel driveway be? +

For a new driveway on bare earth, you typically need a minimum of 8 to 12 inches of total aggregate, laid in lifts (layers). A common structure is large 3-inch stones (tailings) at the bottom for stability, followed by smaller base stone, capped with 2-3 inches of surface gravel.

Can I put new gravel over old grass? +

It is highly recommended to remove the topsoil and organic matter (grass) first. Organic matter rots and compresses inconsistently, leading to potholes and sinking. Always excavate down to the subsoil or use a geotextile fabric separator before laying stone.

What is the difference between specific gravity and bulk density? +

Specific Gravity is the density of the solid rock itself (no air). Bulk Density includes the air voids between the stones in a pile. Calculating aggregate tonnage requires Bulk Density, which is much lower than the solid rock density.

How do I calculate volume for a circular fire pit? +

Select "Circular" mode in our calculator. Measure the diameter (width across the center) of your fire pit circle. The tool automatically applies the formula π × radius² × depth to find the cubic yardage.

Why does the price per ton vary so much? +

Price depends on haul distance (trucking is often more expensive than the stone itself) and geology. If you live in a region with limestone quarries, limestone is cheap. If you live in a sandy coastal area, gravel must be trucked in from far away, increasing the cost significantly.