Concrete Calculator

An 80-lb bag yields about 0.6 cubic feet, while a 60-lb bag yields 0.45 cubic feet. Divide your total cubic feet by the yield per bag, then add 5-10% for waste.

One cubic yard equals 27 cubic feet. Concrete is typically sold by the cubic yard for large projects, but bags are measured in cubic feet yield.

For projects under 1 cubic yard, bags are convenient but labor-intensive. Above 1-2 yards, ready-mix delivery is more cost-effective and saves hours of mixing.

Standard slabs are 4 inches for walkways and patios, 5-6 inches for driveways and garages. Footings and structural elements require engineer-specified depths based on load and soil conditions.

Concrete waste accounts for spillage, uneven subgrade, and over-excavation. A 5-10% allowance ensures you don't run short mid-pour, which can compromise the project.