Short answer
Length × width × depth in feet ÷ 27 = cubic yards. A 12 × 50 ft driveway at 4 inches deep needs about 7.4 cubic yards, or roughly 10 tons. Build a 4-inch base of 3/4 stone with a 2-inch top course.
The math
Convert depth to feet first (4 inches = 0.333 ft), multiply by length and width, then divide by 27 for cubic yards.
Gravel runs about 1.4 tons per cubic yard, so multiply your yardage by 1.4 when a supplier quotes by weight.
- 12 × 50 ft at 4 inches ≈ 7.4 cubic yards ≈ 10 tons
- 10 × 30 ft at 3 inches ≈ 2.8 cubic yards ≈ 4 tons
- 1 cubic yard covers ≈ 100 sq ft at 3 inches
Build it in layers
A driveway that lasts is two materials, not one. Compact 4 inches of 3/4 crushed stone as base, then finish with 2 inches of 3/8 for a surface that walks and drives comfortably.
Crown the center slightly so water runs to the edges instead of pooling and washing ruts.
Maintenance
Expect to add a top-up layer every two to three years, more if you plow. Set plow shoes high in winter or you'll push the driveway into the lawn.
Frequently asked
- How many tons of gravel in a cubic yard?
- About 1.4 tons, varying slightly with stone size and moisture.
- How deep should a gravel driveway be?
- Six inches total: a 4-inch compacted base of 3/4 stone plus a 2-inch top course.