calcs.homes
calcs.homes
Estimate cubic yards, bags, and cost for a concrete slab, footing, or column — this concrete calculator covers foundation pours, driveways, and formula-based estimates for any thickness.
Estimate only — actual needs vary with subgrade and mix. Confirm with your supplier.
We multiply length × width × thickness to get cubic feet, add your waste factor, then convert to cubic yards (there are 27 cubic feet in a cubic yard). Bag count divides that volume by the yield of a 60 lb bag (about 0.45 cu ft) or 80 lb bag (about 0.6 cu ft) — the standard formula ready-mix suppliers and contractors use to calculate 1 yard of concrete.
Materials alone typically run $110–$165 per cubic yard for ready-mix, or use the bag-price field above for a bagged-concrete DIY estimate. Add labor, forms, and rebar for a full foundation cost.
About 60 bags of 60 lb concrete, or 45 bags of 80 lb concrete, make one cubic yard (27 cu ft).
Uneven subgrade, spillage, and over-excavation typically use up an extra 5–10% of material. We default to 10% — uncheck the box to see the exact formula result.