How Much Gravel for a Driveway?

Updated 2026-07-19

A gravel driveway looks like the simplest project on the property — order rock, spread rock, drive on rock — until the first spring thaw turns an underbuilt lane into a rutted mess. The difference between a driveway that lasts ten years and one that lasts ten months is almost never the stone itself. It is the depth, the layers, and ordering the right tonnage the first time.

Gravel is sold by the ton or by the cubic yard, and converting between the two is where most first-time buyers get tripped up. Here is the math contractors actually use, plus the depth and stone choices that hold up under daily traffic.

How deep should driveway gravel be?

For passenger cars and pickups, plan on 4 to 6 inches of compacted gravel in total. That is not one uniform layer — it is a 3 to 4 inch base course of larger, angular crushed stone, topped with 2 to 3 inches of smaller stone that locks together and sheds water. On firm, well-drained soil, 4 inches total is plenty. On soft clay, wet stretches, or any section that will see delivery trucks, trailers, or an RV, go to 6 inches or beyond; some contractors spec 8 to 12 inches under RV pads.

Whatever depth you choose, lay geotextile fabric on the bare dirt first. It costs about 15 to 20 cents a square foot and keeps your expensive stone from migrating down into the subgrade — the number one reason thin driveways disappear into the mud within two seasons.

The tonnage math, worked on a real driveway

Start with square footage: length times width. A common single-car driveway is 12 feet wide by 50 feet long — 600 square feet. The rule of thumb every quarry dispatcher knows: one ton of gravel covers roughly 100 square feet at 2 inches deep. So at 4 inches deep you need one ton per 50 square feet, and at 6 inches, one ton per 33 square feet.

For our 600 square foot drive: at 4 inches total depth, that is 600 ÷ 50 = 12 tons. Push it to 6 inches and you are at about 18 tons. In cubic yards, 600 square feet at 4 inches deep is 200 cubic feet, or about 7.4 cubic yards — and since crushed stone weighs 1.4 to 1.6 tons per yard depending on rock type and moisture, the two methods land in the same place. Order in full tons or half-yards, and always round up, never down.

For sloped, curved, or L-shaped driveways, break the footprint into rectangles, figure each one separately, and add 10 percent for the crown, the curves, and what falls off the truck.

Choose the right stone for each layer

1. Base course: angular crushed stone with fines — sold as crusher run, quarry process, #21A, or item #4 depending on your region. The fines let it compact into something close to concrete.
2. Top course: 3/4-inch crushed stone (#57) or a blend like #411 that still carries some fines for lock-up. It should crunch and knit together under tires, not roll.
3. Never top a driveway with rounded pea gravel or river rock. Round stone never locks; it scatters under tires and ends up in the ditch within a season.
4. Angular beats smooth at every size. Every flat face on a crushed stone is a surface that grips its neighbor when the compactor passes.

Delivery, spreading, and compaction

A tandem-axle dump truck hauls about 13 to 15 tons, so a 12-ton order arrives as a single load — ask the driver to tailgate-spread as he creeps down the drive, and you will move half the rock with a landscape rake instead of a loader. Spread the base course in 2 to 3 inch lifts and run a plate compactor over each lift. A hand tamper is fine for a small parking pad, but across 600 square feet your knees will thank you for the $80 rental.

Crown the finished surface so the center sits about 1/4 inch higher per foot of width — a 12-foot drive should be roughly an inch and a half higher in the middle. Water that sheets off a crowned drive is water that is not carving potholes.

Plan for top-offs

Even a well-built gravel drive wants a refresh every two to four years. A 1 to 2 inch top dressing of #57 stone — about a ton per 100 square feet per inch of depth — brings back the crunch and the crown for a few hundred dollars instead of a few thousand. Keep a note of your original tonnage; the same math runs the maintenance.

Once you have your length, width, and target depth, run them through the gravel calculator to get tons and cubic yards side by side — the fastest way to sanity-check a quarry quote before you commit to a truck.