Why order extra? The headline number is the exact material your project needs. When you actually order, add about 5–10% on top — the “with 5% waste” figure in the result is a safe starting point. That margin covers what you lose to compaction, cuts around edges and corners, and ordinary spillage during handling. It is cheaper to have a little left over than to stop mid-job and wait on a second delivery.
Field notes
Buy about 20% over on any driveway — crushed stone compacts hard, and the number you calculate is the finished volume, not the loose delivery. Use angular crushed stone, not rounded river rock, anywhere tires roll; round stone shifts and ruts. Build it in layers with a plate compactor between each, and set edging first or the gravel migrates into the lawn within a season.
How the gravel calculator works
The math behind the tool:
cubic yards = (length ft × width ft × depth ft) ÷ 27
tons = cubic feet × 100 lb/ft³ ÷ 2000Material density
| Material | Density | Per cubic yard |
|---|---|---|
| Crushed gravel | 100 lb/ft³ | 1.35 tons |
Sources: Oregon State University Extension (soil and compost volume guidance).