Soil for Raised Beds and Garden Projects
Soil is the one material where underestimating is almost universal. A standard 4×8-foot raised bed that's 12 inches deep requires about 1 cubic yard of soil — roughly 27 cubic feet. In bagged garden soil from a home center, that's 13 to 14 bags at 2 cubic feet each. Most people guess they'll need 5 or 6. They're wrong by more than half.
The Soil Calculator handles rectangular, circular, and irregular bed shapes. Enter your dimensions and depth, and it returns cubic yards for bulk delivery or bag counts for pickup. It also accounts for the difference between topsoil (denser, heavier, cheaper) and garden soil mixes (lighter, amended with compost, more expensive per yard).
For raised beds specifically, the standard recommendation is a 60/40 mix of topsoil and compost — or a pre-blended raised bed mix from a landscape supplier. The Compost Calculator can help you figure out the compost portion if you're blending your own.