🪨How Much Gravel for a Driveway or Patio (Depth & Base Layers)

By the CalculatorMulch editorial desk

How deep does gravel go for each job?

Depth is set by load, not by looks. Here is the whole range in one place.

Two rules run through that table. Coarse stone goes at the bottom, fine stone on top — the large angular pieces bridge the soft subgrade and the fines lock the surface together. And washed stone is used wherever water has to move through, because the fines that make a driveway hard are exactly what clogs a drain.

How much does that come to in tons?

Gravel is sold by weight, so every job needs a second conversion after the volume. At a working 1.5 tons per cubic yard, one ton is 18 cubic feet.

Densities vary by stone, and the difference is not trivial on a large order — dense crushed limestone can run near 1.7 tons per yard while washed river rock falls closer to 1.3. Ask the supplier for their figure on anything above five tons, and run it through the cubic yards to tons calculator.

What does a real driveway need?

Take a single-car driveway, 12 ft wide and 50 ft long — 600 square feet — built properly over ordinary subgrade in three layers.

Twenty-five tons. That is the number that surprises people, and it is why gravel driveways are quoted by the truckload. It is also five or six deliveries in a tandem dump truck, or one articulated load if the site can take it.

Add the compaction allowance on top of that. Angular stone with fines loses roughly 20 percent of its loose volume under a plate compactor, so the three layers above want ordering at about 20 tons, 10 tons and 6.7 tons respectively to finish at the stated depths — call it 30 tons of material for a 25-ton finished driveway. Skipping that allowance is why so many driveways end up an inch and a half short of the plan.

Volumes for your own dimensions come out of the gravel calculator, which reports both yards and tons.

What does a patio base need?

Less than a driveway, but with a tighter tolerance. A 200 sq ft paver patio on ordinary ground:

Two mistakes account for most failed patios. The first is using pea gravel as the base — round stone cannot lock together, so it moves under load forever. Base stone must be angular and must contain fines. The second is a thick bedding layer: the sand course is one inch, screeded, and never used to level out a base that was not level. Anything more than an inch of sand will rut under the pavers within a season. Sand volumes come out of the sand calculator.

Which stone size do I actually order?

The single most useful distinction is washed versus with fines. Washed stone has the dust screened out: water runs straight through it, so it belongs in drains, dry wells and anywhere drainage is the job. Stone with fines — crusher run, quarry process — compacts into a hard, near-solid surface, which is what you want under pavers and on top of a driveway, and precisely what you do not want around a drain pipe.

Rounded stone never locks. Pea gravel and river rock look excellent and migrate constantly, so they need steel or timber edging and they should never be walked on in bare feet or used as a base for anything. Sizes and coverage for those two are covered in the pea gravel calculator and the river rock calculator.