Gravel & aggregate
How Much Gravel Do I Need for a Driveway?
By the HomeCalc USAReviewed against our editorial policyLast updated US units and pricing
Multiply length by width in feet, multiply by depth in feet (4 inches = 0.333 ft), then divide by 27 to get cubic yards. For most crushed stone, one cubic yard weighs about 1.4 tons, so a 30 ft x 12 ft driveway at 4 inches needs roughly 4.4 cubic yards, or about 6.2 tons.
Skip the arithmetic: use the Gravel Calculator.
Quick answers on yards, tons and depth: read the Gravel FAQ.
Key takeaways
- Gravel is sold by the cubic yard or by the ton; converting between them needs the stone's density, typically 1.3 to 1.5 tons per cubic yard.
- A new driveway usually needs three layers totaling 8 to 12 inches; a resurface needs 2 to 3 inches.
- Order roughly 10% extra for compaction, spillage and low spots. Compacted crushed stone settles about 20% from loose volume.
- Angular crushed stone locks together and stays put; rounded pea gravel migrates and needs edging.
The formula, step by step
Every gravel estimate is a volume calculation. Suppliers quote in cubic yards (a cube three feet on each side) or in tons, and the only tricky part is converting between the two.
- Measure the driveway length and width in feet. For an irregular shape, split it into rectangles and add the areas.
- Convert your target depth from inches to feet by dividing by 12. Four inches becomes 0.333 feet.
- Multiply length x width x depth to get cubic feet.
- Divide by 27 to get cubic yards.
- Multiply cubic yards by the stone's density (about 1.4 tons per cubic yard for crushed limestone) to get tons.
A worked example
A two-car driveway measuring 30 feet long by 12 feet wide, resurfaced at 4 inches: 30 x 12 = 360 square feet. 360 x 0.333 = 120 cubic feet. 120 / 27 = 4.44 cubic yards. At 1.4 tons per yard that is about 6.2 tons — roughly one full tandem-axle delivery.
The same driveway built new with a 12-inch three-layer section needs about 13.3 cubic yards, or 18.7 tons, split across base, middle and surface stone.
How deep should each layer be?
Soft or clay-heavy soil needs the deeper end of each range plus a geotextile fabric under the base to stop stone punching into the subgrade.
Typical residential driveway section in the US
| Layer | Stone | Depth |
|---|---|---|
| Base | #3 or #4 crushed stone (1.5-2.5 in) | 4-6 in |
| Middle | #57 crushed stone (0.75-1 in) | 3-4 in |
| Surface | #8, #411 or crusher run | 2-3 in |
| Resurface only | #57 or crusher run | 2-3 in |
Coverage per ton, at a glance
These figures assume crushed stone at about 1.4 tons per cubic yard. Pea gravel and river rock are lighter and cover slightly more ground per ton; wet stone weighs more and covers less.
| Depth | Sq ft covered per ton | Sq ft per cubic yard |
|---|---|---|
| 2 in | ~120 | ~162 |
| 3 in | ~80 | ~108 |
| 4 in | ~60 | ~81 |
| 6 in | ~40 | ~54 |
Compaction: why loose volume is not finished depth
Crushed stone loses roughly 15-25% of its loose volume once it is rolled or plate-compacted. If you want a finished 4-inch surface layer, spread closer to 5 inches loose. Estimating tools quote loose delivered volume, so add the compaction allowance yourself rather than assuming the number already includes it.
Rounded stone such as pea gravel barely compacts at all — it stays loose by design, which is why it needs a hard edge to contain it.
Choosing the right stone
- Crusher run (dense-grade aggregate): stone plus fines, packs to a hard surface, best for driving lanes.
- #57 stone: clean, drains fast, no fines, ideal as a middle layer or for French drains.
- Pea gravel: smooth and rounded, comfortable underfoot, migrates under tires unless edged.
- River rock: decorative, poor for driveways, fine for borders and dry creek beds.
Ordering and delivery
A standard tandem-axle dump truck carries about 12-15 tons; a tri-axle carries 18-22 tons. Ordering in full truckloads usually lowers the per-ton delivered price, and most yards charge a flat delivery fee regardless of load size.
Ask the yard whether their quoted yardage is loose or compacted, and confirm the tons-per-yard figure for the specific stone — density varies by quarry and by how wet the stockpile is.
Frequently asked questions
How many tons of gravel are in a cubic yard?
For crushed stone, about 1.3 to 1.5 tons per cubic yard, with 1.4 a safe planning figure. Wet stone sits at the higher end; lightweight decorative rock at the lower end.
How much does a gravel driveway cost?
Material alone commonly runs $15-$75 per ton at the yard depending on stone type and region, plus delivery. Installed cost including grading and compaction is usually quoted per square foot by a contractor.
How deep should gravel be on a driveway?
A new driveway needs 8-12 inches total across three layers. An existing driveway that just needs a refresh takes 2-3 inches of new surface stone.
Do I need landscape fabric under gravel?
On soft, wet or clay soils, yes — a woven geotextile keeps base stone from sinking into the subgrade and greatly extends the life of the driveway. On firm, well-drained gravelly soil it is optional.
Sources and references
- USDA NRCS — Soil texture and drainage basics — Background on subgrade soils that determine required base depth.
- Federal Highway Administration — Aggregate base course guidance — Reference for dense-graded aggregate layer thicknesses and compaction.