Gravel is measured in cubic yards and sold by the ton, and that mismatch is where most orders go wrong. This gravel calculator works out both from the same measurements, so you can quote the supplier the number they actually price against.
Yards in, tons out
A cubic yard of crushed stone at 105 pounds per cubic foot weighs about 1.42 tons. That single conversion is the one to get right, because a quarry quoting $42 a ton and a landscape yard quoting by the yard are not offering comparable prices until you convert.
A 30 by 12 foot driveway at 3 inches deep needs 3.67 cubic yards once a 10% allowance is added, which is 5.2 tons and about $218 at that rate.
Density is not a constant. It moves with stone size and moisture, and a wet load weighs more than a dry one for the same volume. The density field above is there to be changed. Ask the supplier what their material runs at rather than accepting the default, because on a large order the difference is measured in tons.
Depth drives the cost, and it drives it linearly
Area is fixed by the site. Depth is the one variable you control, and it scales the order in direct proportion. On that same driveway:
- 2 inches is 2.44 cubic yards, 3.47 tons, about $146.
- 4 inches is 4.89 cubic yards, 6.93 tons, about $291.
- 6 inches is 7.33 cubic yards, 10.4 tons, about $437.
Specifying an inch more than the job needs is a straightforward waste of budget. Specifying an inch less on a driveway that carries vehicles is a rutting problem you will pay to fix, so this is a decision to make deliberately rather than by rounding.
What depth the job actually calls for
- Walkways and garden paths: 2 to 3 inches over a compacted subgrade.
- Residential driveways: 4 inches of base plus a 1 to 2 inch surface course, laid and compacted in layers rather than in one lift.
- Drainage and French drains: depth is set by the trench, so measure the excavation rather than the surface.
Aggregate compacts as it is rolled, typically by around a fifth from loose to compacted, and that is separate from the waste allowance above. If you are specifying a finished compacted depth, order for the loose volume that compacts down to it.
Ordering without a shortfall
Delivery is the dominant cost on a small load, so a second trip to cover a shortfall usually costs more than the material you were trying not to over-order. The 10% allowance above covers spillage, an uneven subgrade and the material that disappears into the ground on the first pass.
For the bedding layer that goes on top of a compacted base under pavers, the sand calculator handles that separately, and the concrete calculator covers anything being poured rather than spread.
Gravel calculator FAQ
About 1.42 tons for crushed stone at 105 pounds per cubic foot. Denser material runs heavier and a wet load heavier still, so confirm the figure with your supplier before converting a large order.
A 30 by 12 foot driveway at 3 inches deep needs about 3.67 cubic yards, or 5.2 tons, including a 10% allowance. Most residential driveways want 4 inches of base plus a 1 to 2 inch surface course laid in compacted layers.
Four inches of compacted base with a 1 to 2 inch surface course for a residential driveway carrying cars. Paths need only 2 to 3 inches. Going deeper than the job requires scales the cost in direct proportion.
Order in whichever unit your supplier prices in, but convert before comparing quotes. Volume is what the site needs and weight is what the truck carries, so a yard price and a ton price are not comparable until you apply the density.
