How much gravel do you need?
Use the compacted depth — loose material compacts roughly 20–30%.
How this estimate works
The calculator multiplies length by width by compacted depth to get volume, converts to cubic yards, then converts yards to tons using the density of the material you picked. Density is where gravel math usually goes wrong: a cubic yard of crushed stone weighs about 1.4 tons, sand about 1.3, and river rock about 1.5, because rock type, moisture, and gradation all change how much a yard actually weighs. Those per-material figures are labeled approximations — every quarry's product is a little different, and the scale ticket at the yard is the final word. Depth is asked for as the compacted depth because loose stone settles: a load spread 5 inches loose typically compacts to about 4 inches under traffic and weather. The optional 5% waste cushion covers spillage at the edges, low spots in the subgrade, and the thin areas every hand-spread job ends up with.
Worked examples
Standard driveway, 100 × 10 ft at 4 inches. That is 100 × 10 × (4 ÷ 12) = 333 cubic feet, or about 12.3 cubic yards. In crushed stone at 1.4 tons per yard, roughly 17.3 tons — call it 18 with the waste cushion. At $35 a ton, the stone itself runs about $630 before delivery. Most quarries deliver in loads of 10 to 22 tons, so this is a single load.
Garden path, 30 × 3 ft at 3 inches. About 0.83 cubic yards, or 1.2 tons of pea gravel. Small jobs like this are where bagged material sometimes wins: under a ton, the delivery fee on a bulk load can exceed the savings, so price both before you order.
Parking pad, 20 × 20 ft at 6 inches. About 7.4 cubic yards, roughly 10.4 tons of crushed stone. Six inches is base-course territory — if this pad carries vehicles, that depth goes over a compacted subgrade, not straight onto topsoil.