How much gravel do I need?
Area × depth ÷ 324 gives cubic yards, same as mulch — but gravel is sold by the ton as often as by the yard, and a base course compacts: run a plate compactor over crusher run and it loses about 15% of its loose volume, which is volume you have to order. The calculator converts both ways using each material's real density and adds the compaction allowance where the material needs one.
A 300 sq ft patio's 4-inch base course is 3.70 yd compacted — order 4.36 yd loose, which is 6.3–7.0 tons of crusher run. The inch of bedding sand on top is 1.03 yd (1.3–1.5 tons).
Gravel weight: tons per cubic yard
| Material | Tons per yard | Compaction | Use |
|---|---|---|---|
| Crusher run / road base (¾″ minus) | 1.45–1.60 | 15% | Fines + angular stone; locks solid. The paver base layer. |
| Clean crushed stone (#57, ¾″) | 1.35–1.45 | 5% | No fines; drains. French drains, driveways over base. |
| Pea gravel | 1.30–1.40 | 5% | Rounded; never locks. Paths and dog runs, not base. |
| River rock / decorative | 1.20–1.35 | 0% | Ground cover over fabric; order by looks, not layers. |
| Concrete / bedding sand | 1.30–1.50 | 10% | The 1″ screeded layer under pavers. |
| Decomposed granite | 1.30–1.45 | 12% | Compacts to a firm path surface. |
Supplier-published densities; moisture moves them a few percent. A ton of most gravel is about ⅔ of a cubic yard.
"Crusher run" (¾″ minus, road base, ABC — the names vary by region) contains stone dust that locks the angular pieces together when compacted; it's what patios, sheds and driveways sit on. "Clean" stone has no fines, stays loose, and drains — which is exactly why it goes in French drains and why a patio built on it shifts. Pea gravel is round and never locks at all: fine for a path, hopeless as base. Buy the boring gray one for structure and the pretty one for the top inch.
The paver base build-up
The industry-standard stack under concrete pavers, per ICPI guidance: compacted crusher-run base — 4 inches for patios and walks, 8 for driveways, plus a couple of inches on clay or soft soil — then one inch of bedding sand, screeded flat, never compacted, never deeper (thick sand ruts). Geotextile fabric between soil and base is cheap insurance on clay. Excavate base + sand + paver thickness below finished grade, compact the subgrade, then build up in 2-inch lifts, compacting each. The paver mode above sizes both layers and the digging.
Coverage: how far a yard goes
| Depth | 1 cu yd covers |
|---|---|
| 2 in | 162 sq ft |
| 3 in | 108 sq ft |
| 4 in | 81 sq ft |
| 6 in | 54 sq ft |
Loose volume, before compaction. For decorative rock over fabric, 2 in hides the fabric; 3 in stays hidden after the dog.
Ordering and moving it
Gravel yards sell by the ton or the yard — give them square feet and depth and they'll quote either; the calculator's tons figure lets you sanity-check the quote. A ton of gravel is one scoop of a small loader and about the legal payload of a half-ton pickup (which is why the truck is called that — don't put a yard and a half in it). For anything over a few tons, delivery is cheap next to a chiropractor. A wheelbarrow holds about 6 cu ft, so a yard is roughly 4–5 loads; a 300 sq ft patio's base is 20 of them.
Sources: ICPI (Interlocking Concrete Pavement Institute), Residential Paver Installation Guide (base and sand thicknesses); supplier published aggregate densities; NRCS compaction factors for crushed aggregate. Names for ¾″-minus base vary regionally — crusher run, road base, ABC, QP, dense-grade.