
Why size matters when it comes to gravel for a driveway ...
A commonly used gravel size for driveway base layers is #3 gravel. This rock is generally 12 inches in diameter and does double duty by establishing a solid, reliable foundation and providing adequate drainage; both critical factors in driveway construction. #3 gravel is crushed in giant machines and the final product is typically irregular shapes. #4 stone is also commonly used for base layers.