81 cubic yards (400 ft³) of concrete — roughly 667 bags of 80 lb mix. Adjust the thickness below for footings, patios, or driveways.
Enter your exact thickness — the default 4 inches suits patios and shed floors, while driveways often use 5–6 inches. The tool returns the volume plus bag counts for 40, 50, 60, and 80 lb mixes.
Why order extra? The headline number is the exact material your project needs. When you actually order, add about 5–10% on top — the “with 5% waste” figure in the result is a safe starting point. That margin covers what you lose to compaction, cuts around edges and corners, and ordinary spillage during handling. It is cheaper to have a little left over than to stop mid-job and wait on a second delivery.