Concrete Volume Calculator

The Concrete Volume Calculator quickly converts your slab's square footage and thickness to cubic yards of concrete needed, plus the number of 60-lb and 80-lb premix bags. Enter the length, width, and thickness in inches, and get the concrete volume in the units your supplier needs.

Whether you're pouring a patio, driveway, sidewalk, or foundation, concrete volume must be calculated before ordering. Ready-mix concrete is ordered by the cubic yard. Bagged concrete (60-lb or 80-lb sacks) is sold in bags - knowing both numbers lets you compare the cost of mixing your own vs. ordering a delivered mix. A 60-lb bag yields approximately 0.45 cubic feet; an 80-lb bag yields 0.60 cubic feet.

This calculator is optimized for slab-on-grade pours: patios, driveways, garage floors, sidewalks, and shed slabs. For walls, footings, or columns, use our main Concrete Calculator which supports more geometries.