Cubic yards explained for gravel, mulch, and soil
Bulk landscape and aggregate materials are often sold by cubic yard even when your measurements start in feet and inches.
Picture one cubic yardIt is a cube 3 feet long, 3 feet wide, and 3 feet high: 27 cubic feet of volume.
Area and depth create volume
Square footage describes a surface. Bulk material must also have depth. Multiply square feet by depth expressed in feet to get cubic feet, then divide by 27 for cubic yards.
For example, 108 sq ft covered 3 inches deep equals 27 cubic feet, or exactly one cubic yard before allowance.
Coverage changes quickly
At one inch deep, a cubic yard covers 324 sq ft. At two inches it covers 162 sq ft, and at three inches it covers 108 sq ft. Measuring depth carefully matters more than adding a vague extra scoop later.
Loose, compacted, and settled are not identical
Gravel can compact under equipment and traffic. Mulch settles over time. Soil can change volume with moisture and handling. Tell the supplier the finished purpose and depth so their recommended conversion matches the material and placement method.
Cubic yards do not equal tons
Volume-to-weight conversion depends on density. Two products occupying the same cubic yard can weigh differently. Use the supplier’s tons-per-yard number for the exact material instead of treating a generic conversion as a guarantee.
- Calculate each shape separately.
- Add an allowance only after net volume is known.
- Round according to the supplier’s sales increment.