Backing Calculator 🖼️
Calculate backing fabric yardage for your quilt. Get seam direction, panel count, and exact yardage based on quilt size, overhang allowance, and fabric width.
How to Use the Backing Calculator
Enter your quilt's finished width and height. The overhang allowance adds extra fabric on each edge for mounting in your quilting frame (typically 2" per side = 4" total).
The calculator determines whether to seam your backing panels horizontally or vertically based on which direction uses less fabric. The seam is placed away from the quilt center when possible.
Prewash your backing fabric before cutting — quilting cotton typically shrinks 2-5%. Use a walking foot when sewing long backing seams to prevent shifting and stretching.
Frequently Asked Questions
How much overhang do I need for quilt backing?
For home machine quilting, add 2-4" per side. For long-arm quilting, add 4-6" per side as long-arm frames require more overhang. The QuiltMetric default is 2" per side (4" total).
Should I seam my backing horizontally or vertically?
The seam direction depends on which orientation uses less fabric. QuiltMetric automatically calculates both options and recommends the most fabric-efficient direction. Generally, place the seam away from the center of the quilt when possible.
Do I need to prewash quilt backing fabric?
Yes, prewashing is strongly recommended. Quilting cotton typically shrinks 2-5% when first washed. If you don't prewash, your finished quilt may pucker or shrink unevenly after the first wash.
Can I use a single piece of fabric for quilt backing?
For quilts up to about 40" wide, you can often use a single width of fabric (40-44" WOF) without seaming. For wider quilts, you'll need to seam multiple panels. Wide backing fabric (108" WOF) is available and eliminates the need for seaming on most quilts.