Gravel Tons vs Cubic Yards: Which Number Should You Order?

Two different numbers describe the same pile of gravel. A cubic yard is a volume, and a ton is a weight. Converting one to the other needs the density, and the density belongs to a particular stone.

There is no single conversion

Density depends on the kind of stone, its grading, its moisture and whether the figure is for loose or compacted material. The Washington State DOT’s design manual, for example, recommends 3,700 lb per cubic yard, or 1.85 tons, for compacted aggregate, with sandy grading lower and coarse grading higher. Other published figures differ from it, which is why a single conversion would mislead.

The planner starts from 1.5 tons per cubic yard, labels it a rough planning value, and lets you change it. That is a convenience for planning, not a published standard.

The same job at four densities

A 40 × 12 ft area at 4 inches deep is the same volume every time: 6.52 yd³. Only the weight moves:

Across those four assumptions the estimated weight differs by 3.6 tons for one driveway. That spread is the whole reason to ask: the right figure is the one your supplier uses to bill you.

What to order

If your supplier sells by the ton, ask what they assume per cubic yard for the stone you want, replace the planner’s density with it, and order the resulting tons. If they sell by the yard, order the volume. If you want to compare quotes, convert both to the same unit with the same density.