How Much Gravel Do I Need?
Multiply area × depth to get cubic feet, divide by 27 for cubic yards, then multiply by about 1.4 for tons.
Choosing a depth
Use 2–3 inches of gravel for paths and beds, and 4–6 inches for driveways, usually in a base and topcoat layer.
Worked example
A 20 ft × 10 ft driveway at 4 inches deep = 200 × (4 ÷ 12) = 66.7 cubic feet = 2.47 cubic yards ≈ 3.5 tons.