Driveway gravel calculator
Most gravel driveways are two layers: coarse base stone that gets compacted, then a thinner top layer. Enter both and get each order on its own.
Common driveway widths
| Driveway | Width people commonly use |
|---|---|
| Single car | 10-12 ft (3-3.7 m) |
| Two cars side by side | 20-24 ft (6-7.3 m) |
| Room to open doors or walk past | Add 2-3 ft |
Check local rules for where the driveway meets the street; many towns set the width of the apron.
How deep should a gravel driveway be?
A common build for cars on firm ground is about 4 to 6 inches of compacted base with 2 to 3 inches of top stone. Soft clay, wet ground or delivery trucks call for a deeper base, sometimes much deeper.
Those are rules of thumb. If an installer or your local supplier has looked at the site, use their depths.
Why the base needs a compaction allowance
Base stone has fines in it, and a roller or plate compactor packs it down. To finish at 4 inches you have to spread more than 4 inches of loose stone. Suppliers often suggest adding somewhere around 10 to 20 percent, but ask for the figure for the product you buy and enter it as compaction.
Worked example: a 12 × 60 ft driveway
- Area: 12 ft × 60 ft = 720 square feet.
- Base, 4 inches (0.333 ft): 720 × 0.333 = 240 ft³. Add 15% compaction: 276 ft³, or 10.22 cubic yards.
- Base weight at a supplier density of 120 lb/ft³: 276 × 120 = 33,120 lb, or 16.56 US tons.
- Top layer, 2 inches (0.167 ft): 720 × 0.167 = 120 ft³. Add 5%: 126 ft³, or 4.67 cubic yards.
- Top weight at 100 lb/ft³: 126 × 100 = 12,600 lb, or 6.30 US tons.
- Order: about 16.6 tons of base and 6.3 tons of top stone, 22.86 tons in all.
Common questions
How many tons of gravel do I need for a driveway?
Work out each layer: length × width × depth in feet gives cubic feet. Add compaction for the base, then multiply by the supplier's density and divide by 2,000. A 12 × 60 ft driveway with a 4 inch base and 2 inch top comes to about 23 tons at typical densities.
Should the base and top layer be the same stone?
Usually not. The base is a mix with fines that locks together when compacted; the top is a cleaner, more even stone that looks tidy and drains. Ask for both by name and get the density of each.
Do I need fabric under a gravel driveway?
On soft or clay soil, many installers lay a woven geotextile under the base so the stone does not sink into the mud over time. On firm, well-drained ground it is often skipped.