A gravel driveway is usually 4 to 8 inches thick, built in layers. A 50 foot by 12 foot drive at 6 inches needs about 11 cubic yards before compaction.
Measure and choose a depth
Measure the length and width of the drive. For a stable surface on firm ground, use 4 inches. Use 6 to 8 inches on softer soil, or when you will drive heavy vehicles.
Layers
Most gravel drives have a coarse base of larger stone, a middle layer, and a finer top layer. Calculate each layer separately and add them together. Ask the supplier which sizes they recommend for your soil.
Example
A 50 foot by 12 foot drive is 600 square feet. At 6 inches (0.5 feet), that is 300 cubic feet, or 11.1 cubic yards. Add 15 percent for compaction and you reach about 12.8 cubic yards. At 1.4 tons per cubic yard, that is about 18 tons.
Tips
Crown the center so water runs off the sides. Use edging or a ditch to hold the gravel. Fabric under the base keeps it from mixing with soft soil.
Frequently asked questions
How thick should a gravel driveway be?
Commonly 4 to 8 inches in total, depending on soil and traffic.
How many tons of gravel for a driveway?
Roughly 1.4 tons per cubic yard, so an 11 cubic yard job needs about 15 tons.
Should I order extra?
Yes. Add 10 to 15 percent for compaction.