Enter dimensions and depth and the calculator applies the 100 lb/ft³ density to return tons and cubic yards.
Bulk gravel is delivered by the ton, so this view leads with tonnage. Order roughly 20% over your finished volume: crushed stone compacts hard and the calculated figure is the compacted result, not the loose delivery.
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.