How this calculator works
It multiplies area by depth for the volume, then shows it as cubic yards (bulk delivery) and 40 lb bags, which hold roughly 0.75 cubic feet each.
Worked example — a 20 ft × 10 ft bed at 3 inches:
200 × (3 ÷ 12) = 50 cubic feet → ÷ 27 = 1.85 cubic yards, or about 67 bags.
200 × (3 ÷ 12) = 50 cubic feet → ÷ 27 = 1.85 cubic yards, or about 67 bags.
Bags or bulk delivery?
Bags suit small top-ups. For anything over about 1 cubic yard, bulk topsoil delivered by the yard is far cheaper than buying dozens of bags.
Frequently asked questions
How many bags of topsoil in a cubic yard?
About 36 bags of the 40 lb (0.75 cu ft) size make one cubic yard.
How deep should topsoil be for grass?
Aim for 3–6 inches of quality topsoil for a healthy new lawn.