How this gravel calculator works
Volume in cubic yards is area (length × width in feet) times depth in feet (depth in inches ÷ 12) divided by 27 — because one cubic yard is 27 cubic feet. The calculator then multiplies by a typical density for the material: about 1.35-1.40 tons per cubic yard for gravel and crushed stone, 1.35 for sand, 1.10 for topsoil and 0.45 for mulch.
Order 5-10% extra because gravel compacts and settles after spreading. For driveways, a 4-6 inch layer over a compacted base is typical; heavier traffic needs 6-8 inches. Always confirm the density with your supplier — wet sand weighs much more than dry sand, so tonnage estimates can swing 10-20%.
Common uses and depths
- Driveway base: 4-6 inches (heavy use 6-8 inches)
- Patio base: 4 inches of compacted crushed stone
- Drainage around foundations: 6-12 inches
- Garden mulch: 2-3 inches