Gravel Calculator

Gravel is sold two ways: by the cubic yard from a landscape yard, or by the ton from a quarry or aggregate supplier. Cubic yards is a volume measurement and tons is a weight measurement, so converting between them requires knowing the density of the material you are buying. Density varies with the stone type, the size of the pieces, and whether the material is wet or dry, but working averages get you close enough to order.

The volume math is the same as any other loose material: length in feet times width in feet times depth in feet, divided by 27. Depth is almost always given in inches, so remember to divide inches by 12 first. A forty foot long, ten foot wide driveway covered four inches deep is 40 x 10 x (4/12) / 27 = 4.94 cubic yards. To convert to tons, multiply cubic yards by the density in tons per cubic yard. Common densities: pea gravel about 1.35, washed river rock about 1.4, dense-graded road base about 1.5, and rip rap about 1.7.

So the same driveway needs about 4.94 x 1.4 = 6.9 tons of #57 crushed stone, or 4.94 x 1.5 = 7.4 tons of road base. Round up to whole tons at the quarry ticket, and always order at least ten percent extra for spread loss, low spots in the subgrade, and the inevitable settling that happens after the first few rain events.

Gravel is not one product. What you order changes based on the job and the finish you want. Number 57 stone, the classic quarter-to-three-quarter inch angular crushed limestone or granite, is the workhorse driveway and drainage material because it locks together when compacted and drains freely. Number 8 is smaller, roughly three-eighths inch, and shows up as topping for driveways where a smoother rolling surface matters. Number 4 is the big one to two inch stone used as base under railroad-style trackways or under number 57 in soft ground.

Pea gravel is rounded, three-eighths inch or so, and is a decorative or comfort material. It looks good, feels good under bare feet around a pool, and does not lock together, which means it moves under load. Do not use pea gravel as a driveway surface unless you want to rake it back into place every month. Road base, sometimes called flex base or crusher run in Texas, is a graded blend of stone dust up through one and a half inch stone that compacts to a hard surface for driveways, parking areas, and construction pads.

For drainage projects, always specify washed stone. Unwashed material carries fines that clog drain pipe holes and fill the voids the drain relies on. For hardscape and paver base, road base or dense-graded aggregate compacts to a stable subbase where washed stone would shift.

A gravel driveway needs enough depth to carry vehicle loads without pumping mud through in wet weather. On stable subgrade like sandy loam, four inches of number 57 over a compacted base is usually enough for passenger vehicles. On clay subgrade, and most of North Texas is clay, plan for six to eight inches of material in two lifts: three or four inches of one-and-a-half inch base rock compacted with a plate compactor or a small roller, then two to four inches of number 57 as the driving surface.

Compaction is where amateur driveways fail and professional driveways last. Loose gravel dumped from a truck settles unevenly and traps water in the low spots. Compacted base rock creates a solid platform the top course rests on. If you skip the compaction step, plan on adding another ton or two of stone every year to keep the surface level.

For a French drain or foundation drain trench, the depth is dictated by the invert of the pipe and the coverage over the pipe. A typical residential French drain trench is six to eight inches wider than the pipe and eighteen inches deeper than the finished grade, filled with washed number 57 stone wrapped in filter fabric. Volume math is the same rectangle formula, just with narrower widths and deeper depths.

In North and Central Texas, most residential gravel is quarried limestone from the Hill Country or Central Texas, or granite trucked in from the Marble Falls area. Rio grande rock and river gravel from the Colorado and Brazos systems show up in decorative work. Quarry prices are quoted per ton at the pit. Trucking is a separate line item, usually per mile or per load, and it can double or triple the delivered cost of the stone once you are more than an hour from the quarry.

A tandem dump truck legally carries about 12 to 16 tons in Texas depending on the axle configuration. A side-dump can move 22 to 25 tons per load. If your driveway needs less than 12 tons, you are paying for a full truck no matter what, so it often makes sense to add the extra depth or extend the driveway rather than leave capacity on the table.

Spreading is the sweat labor. Ten tons of gravel spread by hand with rakes and shovels is a long afternoon. Ten tons spread with a skid steer and a landscape rake is under an hour. For any driveway job over about five tons, a rented skid steer pays for itself in labor saved and in a better finished surface.

Gravel work is a search-driven business. Homeowners with a muddy driveway type "gravel driveway near me" or "driveway rock delivered" into Google and hire whoever answers first. If your name is not on that first page for the towns you serve, you do not exist for that customer.

Peak Local Leads builds and ranks local websites for one gravel and grading contractor per market. We cover the upfront cost, you answer the calls free for seven days, and only pay a flat monthly if the work is real. If you would rather own the phone in your county than pay per lead to a broker, that is what we do.