Estimate gravel, crushed stone, or landscape rock by volume, weight, bags, and bulk order size.
After calculation, use the bag count when buying retail bags or hauling material by hand. Use the bulk order when a supplier sells by ton, cubic yard, cubic meter, or minimum delivery increment. Density changes the final weight, so adjust that field when your supplier gives a specific value.
Formula: volume = area x depth. Adjusted volume = volume x (1 + extra margin / 100). Weight = adjusted volume x material density. Bags and bulk orders are rounded up using the package size or order increment you enter.
Reference examples: in US units, 12 ft x 8 ft at 3 in deep, 10% extra, and 100 lb/ft³ density gives 26.4 cu ft, about 0.98 cu yd, and 1.32 US ton; 50 lb bags round to 53 bags and 0.25 US ton bulk increments round to 1.50 US ton. In metric units, 3 m x 2 m at 5 cm deep, 10% extra, and 1600 kg/m³ gives 0.33 m³ and about 0.53 t; 20 kg bags round to 27 bags and 0.1 m³ increments round to 0.4 m³.
Density is an estimate and can change by stone type, moisture, grading, and how tightly the material is compacted. Use supplier density or weight-per-volume data when available. The extra margin is user-controlled because decorative beds, walkways, driveways, and compacted bases need different reserves.
Sources support the length x width x depth volume method, round-up buying practice, typical material density context, and crushed stone aggregate background.
Use these related calculators before buying outdoor or construction materials.
Last reviewed: 6/24/2026