Fill Dirt Guide
Fill dirt is the cheapest bulk material -- unscreened subsoil used for grading, backfilling, and raising elevation. It's not suitable for planting (low organic content, may contain clay, rocks, and debris) but it's perfect for structural fill under slabs, behind retaining walls, and for general grading work.
Fill dirt weighs about 2,000 lb per cubic yard (1 ton). Many excavation contractors will deliver it for free or nearly free -- they need to get rid of dirt from dig sites, and your yard is a disposal option. Check local classifieds and excavation companies before buying from a landscape supplier.
Screened fill (rocks and debris removed) costs $10-20 per cubic yard. Unscreened fill is often free for pickup or $5-10 per yard delivered. For any application where the fill will be under a structure, use clean fill free of organics, which decompose and cause settling.