Making a queen-size quilt involves piecing together seemingly countless small bits of fabric to create a design. However, beneath the beautiful design of a queen-sized quilt are yards and yards of backing fabric that must be accounted for when calculating the amount of fabric needed to finish the quilt. Determining how much backing fabric to buy varies depending on the size of your finished quilt and the width of the backing material you purchase.
Your backing fabric should be 6 inches longer and wider than your finished queen quilt top. When the quilt top is centered on the backing fabric, you will have a 3-inch allowance on all sides. This allowance gives you room to properly align your quilt top, batting and backing.
Although a queen-size mattress is standard at 60 by 80 inches, queen-size quilts are anything but standard. The quilt must be larger than the mattress so that it can hang down over the edges of the mattress, but the amount of overhang varies. Some queen quilts are designed as comforters, which are tossed on top of the mattress for a casual look. A common finished size for a queen-size comforter is 84 by 94 inches. This width covers your 60-inch-wide queen-size mattress top, with 12 inches hanging down on each side, and is 14 inches longer than the head-to-foot length of your mattress.
Other queen quilts are bedspreads that hang down farther on the sides of the bed--sometimes coming all the way down to skim the floor--and are long enough to go up and over the pillows. If you want a spread this large and the top of your mattress is 24 inches from the floor, the finished width needs to be 108 inches and the finished length needs to be about 116 to 120 inches, depending on the size of your pillows and how much you want to tuck under the front edge of them.
After you have decided how large you want your finished quilt to be, you then can calculate how much backing you have to purchase.
Some extra-wide backing fabric is sold in widths of up to 118 inches. If you purchase fabric this wide and have made a queen-sized comforter using the common queen precut batting size of 90 by 108 inches, you can cut one large rectangle of backing fabric to attach to your quilt top. Simply buy 2 3/4 yards of 118-inch fabric.
If your quilt is not standard size and/or the backing fabric you have chosen is not extra wide, you will need to do a few calculations to determine how much fabric to buy to piece together strips of fabric that will run horizontally across the quilt.
Measure the width of your finished quilt top, and add 6 inches for the allowance. Divide this total by 36 inches to determine the number of yards needed to go across one run of the quilt. The number of strips you need depends on the width of the fabric. Measure the total finished length of your quilt top (with allowance), and divide it by the width of the fabric. Remember to include several inches for seam allowances needed to piece together the strips. Typically, three horizontal strips of fabric are pieced together to cover a queen-size quilt.
For example, if your finished quilt width with allowance is 126 inches, you need 3 1/2 yards of fabric to go across it. If the fabric is 45 inches wide and your finished quilt length with allowance is 132 inches, you’ll need three strips of 3 1/2 yards, or 10 1/2 total yards of fabric.