Just like its name suggests, longarm quilting uses a longarm quilting machine. These machines have a larger arm space (also called throat space), than a sitdown home machine.
The quilt top, batting and back are attached into a metal frame. The sewing machine moves over and sews all three layers at once. Quilting on a longarm saves time and sanity.
calculating square inches of your quilt top
* calculator is a tool that provides an estimate of quilt costs, not guaranteed cost.