A gravel driveway calculator works out the stone for a driveway by multiplying its length × width × depth, then converting to tons and cost. The catch is depth: a driveway is built in layers totalling 8–12 inches, so estimate each layer, not one thin 4-inch pour.
How much gravel do I need for a driveway?
For a single top layer, a gravel driveway needs its area (length × width in feet) multiplied by the layer depth in feet, divided by 27 for cubic yards, then multiplied by about 1.4 for tons. A 12 ft × 40 ft single-car driveway at 4 inches works out to roughly 5.9 cubic yards — about 8.3 tons — once a 10% waste allowance is added.
A driveway is not one layer, though. A driveway built to last is three layers of different stone, so the honest way to estimate a full build is to run the calculator three times — once per layer — and add the results. Set the width and length once, then change only the depth for each layer.
How deep should a gravel driveway be?
Build a gravel driveway 8–12 inches deep in total, made up of three compacted layers. Each layer does a different job: the base spreads the load, the middle bridges and drains, and the top gives a smooth, tire-friendly surface. Skipping straight to a thin decorative layer over bare soil is the single most common reason driveways rut and pump mud.
| Layer | Stone | Depth | Job |
|---|---|---|---|
| Base | #3 / large crusher run (2–4") | 4 in | Load spreading, stability |
| Middle | #57 crushed gravel (¾") | 4 in | Drainage, locking layer |
| Top | #57 or crushed / decorative | 2–4 in | Driving surface |
Order stone for the loose depth, not the finished depth. Each layer compacts by roughly a quarter as it is rolled, so 4 inches loose finishes near 3 inches — build that into your order rather than coming up short.
What kind of gravel is best for a driveway?
Angular crushed stone is best for a driveway because its sharp faces interlock and stay put under weight, while smooth, rounded stone rolls and scatters. Use crusher run (a mix of crushed stone and stone dust) for the base — the dust binds and compacts almost like concrete — then #57 crushed gravel for the middle and top. Save rounded pea gravel for paths and patios, not driveways, where it migrates into ruts. The gravel sizes guide shows exactly what each grade looks like.
How much does a gravel driveway cost?
A gravel driveway costs roughly $1 to $3 per square foot in materials for a full-depth, three-layer build, before delivery and grading. Crusher run is the cheapest layer at about $20–$35 per ton; #57 and decorative top stone cost more. On a 480-square-foot single-car driveway, that is often $600–$1,400 in stone. Delivery, machine grading and a geotextile fabric add to it — the cost per ton guide itemizes each line so you can build a real budget.
What size is a single-car vs a two-car driveway?
Plan a single-car gravel driveway 10–12 feet wide and a two-car driveway 20–24 feet wide; length is whatever your lot needs. Add a couple of feet of width for opening doors and walking around a parked car. These footprints drive the tonnage more than anything, so measure the real area before you order.
| Driveway | Size | Area | Top layer (≈) |
|---|---|---|---|
| Single car, short | 10 × 20 ft | 200 sq ft | 2.4 yd³ · 3.4 tons |
| Single car, long | 12 × 40 ft | 480 sq ft | 5.9 yd³ · 8.3 tons |
| Two car | 20 × 20 ft | 400 sq ft | 4.9 yd³ · 6.8 tons |
| Two car, long | 24 × 40 ft | 960 sq ft | 11.7 yd³ · 16.4 tons |
Tips for a driveway that lasts
- Lay geotextile fabric over the graded soil before any stone — it stops the base sinking and blocks weeds.
- Compact every layer with a plate compactor or roller before adding the next; loose layers never firm up on their own.
- Crown the surface — make the center about 2 inches higher than the edges so water sheds instead of pooling and washing ruts.
- Add a border of timber, steel edging or larger stone to keep the gravel from spreading into the lawn.
- Top up every year or two; driveways lose a little stone to plowing and tires, and a fresh layer of #57 keeps them level.