Calculate soil volume for containers and raised beds.
Container gardening requires more soil than most people expect. A standard 4×4 ft raised bed, 12" deep, needs 16 cubic feet of mix. Potting soil is sold by volume: common bags are 1, 1.5, or 2 cubic feet. For raised beds, use a mix of 60% topsoil, 30% compost, 10% perlite or coarse sand. For containers, use soilless potting mix (peat/coir, perlite, vermiculite) — garden soil compacts and drains poorly in pots. Buy 10% extra to account for settling. Potting mix compresses over time; top off annually. For large raised beds, bulk delivery of garden mix (sold by cubic yard) is more economical than bags.