Gravel: Tons per Cubic Yard and How Much to Order

Gravel is one of those materials where the person selling it thinks in tons and the person laying it thinks in cubic yards. Converting between them is simple once you know the density: crushed stone weighs about 1.4 tons per cubic yard, so a yard of it is roughly 2,800 pounds.

Tons per cubic yard by material

These are typical figures for dry or slightly damp material. Your supplier's own number is the one to trust, since stone size, moisture and the type of rock all change the weight.

As a rule of thumb, you can take a ton of gravel as roughly 2/3 to 3/4 of a cubic yard, or about 20 cubic feet.

How to calculate how much gravel you need

1. Multiply length × width (in feet) to get the area in square feet.
2. Choose a depth in inches and divide by 12.
3. Multiply area × depth (in feet) to get cubic feet, and divide by 27 for cubic yards.
4. Multiply by the tons per cubic yard for your material.

Example: a 20 × 10 ft path, 4 inches deep, in crushed stone. 200 × 0.333 = 66.7 ft³, which is 2.47 yd³ or 3.46 tons.

The gravel calculator does it for you for any shape, and compares the cost.

How deep should the gravel be?

• Decorative beds and ground cover: 2 to 3 inches over landscape fabric.
• Walking paths: 3 to 4 inches, ideally over compacted soil and fabric. Use crushed stone with fines (which locks together) for the base and a finer top layer.
• Patio and paver bases: 4 to 6 inches of compacted crushed stone (see the paver base guide).
• Driveways: 4 to 8 inches of compacted aggregate, in layers, and deeper on soft ground. Use crushed stone, not rounded pea gravel or river rock, which do not compact and will shift under tyres.
• Drainage trenches: depth as the plan calls for, typically with washed stone around perforated pipe.

Allow for compaction and waste

Loose stone is bigger than the same stone compacted. Gravel bases compress by roughly 15 to 25% when you tamp them down, so if you want a 4 inch finished base, order enough loose material for about 5 inches. Add another 5 to 10% for spillage and uneven ground. This is why the calculator has a waste field set to 10%.

Choosing the right stone

• Crushed stone (angular): locks together. Best for bases, driveways and paths that need to stay put.
• Pea gravel (rounded): comfortable underfoot and good for play areas and dog runs, but it migrates and is hard to walk on in deep layers.
• Road base or "crusher run": a mix of stone and fines that compacts into a firm surface. It is the usual choice under pavers and for driveways.
• River rock and decorative stone: for looks. Expensive, and not suited to areas that carry traffic.

Ordering tips

• Check whether the price is per ton or per cubic yard, and whether delivery is included. Delivery minimums often matter more than the material price.
• Know where the truck will tip. A dump truck can carry about 10 to 15 tons, but cannot go on soft lawns and needs overhead clearance.
• Pick up small amounts yourself. A typical pickup bed can safely carry about 1 to 1.5 tons of stone. Check your vehicle's payload rating.
• Lay landscape fabric first on paths and beds to stop the stone sinking into the soil.