From Square Feet to Tons on the Truck

Every gravel order starts with the same arithmetic: area times depth gives volume, and volume divided by 27 converts cubic feet to the cubic yards suppliers work in. The complication is that most yards sell by weight rather than volume, so the number you actually need to place an order depends on the density of the specific material. Crushed stone runs about 100 pounds per cubic foot, base gravel closer to 110, and that difference alone changes a five-yard order by nearly a ton.

Why Compaction Changes What You Order

The most common way to under-order is to calculate the finished dimensions and stop there. Well-graded materials like crusher run contain a range of particle sizes, and when compacted the fines migrate into the voids between larger stones — the same mass occupies noticeably less space. Losing 20 to 25% of loose volume is normal for base gravel. Uniformly sized decorative stone such as river rock has nowhere for its particles to go and barely settles at all, which is why the compaction allowance here defaults differently for each material rather than applying one blanket figure.

Choosing Depth for the Job

Depth is where most of the cost lives, since it scales the entire order linearly. Garden paths and decorative beds work at 2 to 3 inches. A residential driveway wants 4 to 6 inches of compacted base plus a 2 to 3 inch surface course. Anything carrying loaded trucks needs 8 to 12 inches, and critically, it needs to go down in separate lifts each compacted on its own — a single thick pour will not densify properly no matter how many passes the roller makes. One ton of typical stone covers roughly 240 square feet at 1 inch, 120 at 2 inches, and 60 at 4 inches.

Bulk Versus Bags, and the Cost of Running Short

Past about one cubic yard the economics decisively favor bulk delivery. Half-cubic-foot bags work out to well over $150 per cubic yard once you account for the packaging premium, against $40 to $90 per ton delivered in bulk. Bags earn their place only for small repairs or where a truck genuinely cannot reach. That said, the real financial risk on a gravel job is not the material rate — it is a second delivery fee. A 10% waste allowance on a straightforward rectangle, or 15% on irregular or sloping ground, costs far less than paying to send a truck back out for the last half yard.