Gravel depth, compaction, and ordering by the ton

In-place volume vs what you order

Area × depth gives the volume of the finished layer. Gravel arrives loose. If it will be rolled, compacted or driven on, it settles into less space, so you need more loose material than the finished volume. If it’s a decorative layer that won’t be compacted, the difference is smaller.

Why there’s no single compaction factor

How much a gravel compacts depends on the stone, its size range, how angular it is, its moisture, and the equipment used. Online calculators use different fixed percentages that don’t agree with each other, and we found no manufacturer or industry source that sets one figure for all gravel. So our calculator lets you choose an extra allowance and never adds one on its own.

The most reliable way to decide: tell your supplier the area and the compacted depth you want, and ask how much of their product to order.

Cubic yards to tons

Many yards sell by weight. Weight per cubic yard varies with the stone and its moisture, so ask for the figure for the exact product. Then multiply:

• Path: 10 × 20 ft at 3 in = 50 cu ft = 1.85 cu yd.
• With a 10% allowance you chose: 2.04 cu yd.
• If the yard quotes 1.4 tons per cubic yard for that product: 2.04 × 1.4 = 2.85 tons.

The 1.4 is only an illustration. Use your supplier’s number.

Depth depends on the job

A decorative top layer on a path is thinner than a base course under pavers or a driveway. Driveway and base depth depend on soil, drainage and the loads it will carry; that’s a design decision for your supplier, installer or local guidance, not a number to guess.