Once you finish piecing a quilt top, most of your work is done, but the quilt is far from complete. Determine how much backing and binding fabric you need to make your quilt a complete and cozy work of art.
Lay your quilt top on a flat surface. Measure and record the length of each quilt side.
Determine how to lay out the fabric back. Quilting fabric is generally 44 inches wide. You will have to remove approximately an inch of salvage, so if a side of your quilt measures less than 43 inches, use one piece of fabric for the quilt back. If your quilt is wider, you will need to sew two or more pieces of fabric together. Some quilt shops carry wider quilt backing that you may consider using for a larger quilt.
Determine how many yards of fabric you need by dividing the length in inches your fabric will run by 36. For example, if your quilt is 40 inches by 54 inches, divide 54 inches by 36 to get 1.5 yards of fabric. If your quilt is 80 inches by 54 inches, you will need twice the fabric, or 3 yards. A fabric shop can help you convert inches to yards if you are unsure.
Calculate the diameter of your quilt by adding the length of each side together. Determine how wide you want the quilt binding to be. There are online calculators or guides at quilt shops to help you determine how much fabric you need for a binding, but a 1/2-inch binding for any standard-size quilt usually takes no more than 1 yard of fabric. If you plan to put a wider binding on a quilt over 250 inches in diameter, purchase a yard and a half of fabric.