A worked example
A 300 sq ft path at a 4-inch depth with a typical density of 1.4 tons/yd³ needs about 5.19 tons of gravel.
Frequently asked questions
Why does gravel get sold by weight instead of volume?
Trucking and scale equipment make weight far easier to measure precisely at a quarry or supplier than volume, and weight is unaffected by how loosely or tightly the material happens to be piled — which is why suppliers price and deliver gravel by the ton.
Why does density vary by material?
Different stone types and gravel sizes pack differently — angular crushed stone settles differently than smooth rounded pea gravel, and denser stone types simply weigh more per unit volume than lighter ones.
How deep should a gravel driveway base be?
It depends on the application, but a base layer is often 4-6 inches deep for a driveway, sometimes built up in multiple compacted layers for better stability under vehicle weight.