Gravel is the one landscape material commonly sold by the ton rather than the yard, so you need both numbers. A cubic yard of gravel runs roughly 2,300 to 3,400 pounds depending on stone size and how wet it is — call it 1.4 tons for dry crushed stone in the quarter to two inch range.
Depth by use
A residential driveway needs about four inches of finished gravel on top. Building one from bare ground takes more: roughly three inches of coarse base stone, then three inches of the finish layer, so six inches total.
Walking paths need a minimum of three inches. Less than that and the stone scatters and the ground shows through within a season.
French drains and drainage beds are usually filled the full depth of the trench with clean, washed stone that has no fines in it.
Yards or tons — and why the answer differs
Volume is what fills the space. Weight is what the truck carries. Suppliers quote whichever suits their scale, so it pays to have both figures before you call.
Converting between them depends entirely on density, and density depends on the stone. Pea gravel, crushed limestone and river rock at the same volume can differ by 1,000 pounds per yard. If your supplier publishes a density for the exact product, put that number in the density field above rather than trusting a generic average — including ours.
Compaction
Gravel delivered loose and then compacted loses volume, typically 10 to 20 percent for a driveway base that gets rolled or plate-compacted.
If the finished depth matters — and for a driveway it does — order the extra. Setting the waste factor to 15 percent is a reasonable starting point for anything that will be compacted.
Stone size
Larger stone, three quarters of an inch and up, drains well and stays put under vehicles, but it is uncomfortable to walk on and hard to shovel snow off.
Smaller stone and pea gravel are pleasant underfoot and terrible under tires — it migrates, and it ends up in the lawn. For a driveway, angular crushed stone locks together far better than rounded river gravel.