Gravel is figured by volume, then often converted to tons for ordering. The formula is cubic yards = (length × width × depth) ÷ 27, with measurements in feet (so a depth in inches gets divided by 12 first).
Coverage by depth
Because depth changes everything, it helps to know what one cubic yard covers:
| Depth | Coverage per cubic yard |
|---|---|
| 1 inch | ~300 sq ft |
| 2 inches | ~150 sq ft |
| 3 inches | ~100 sq ft |
| 4 inches | ~80 sq ft |
Worked example
A driveway 40 ft long and 10 ft wide (400 sq ft) at 3 inches deep: 400 × (3 ÷ 12) = 100 cubic feet; ÷ 27 = 3.7 cubic yards. Round up to 4 to allow for compaction and an uneven base.
Cubic yards to tons
Most gravel weighs about 1.4 tons per cubic yard (roughly 2,800 lb), though it varies from about 1.4 to 1.7 tons by stone type. Our 3.7-yard driveway is therefore around 5.2 tons. Suppliers often sell by the ton, so this conversion matters at quote time.
Frequently asked questions
How much area does a ton of gravel cover? About 100 sq ft at 2 inches deep, since a ton is roughly 0.7 cubic yards.
How deep should gravel be? 2 inches for paths, 4–6 inches for driveways, in layers for heavy use.
Should I order extra? Yes — add about 10% for compaction and settling into the base.