Method
Required backing width/length = quilt size + 2×overhang. We compare piecing panels across the width versus the length and pick the orientation that uses less fabric, adding a little length for seam allowances when panels > 1.
Worked example
80×90" quilt, 4" overhang, 44" fabric: typically two panels and on the order of 5+ yards depending on seam direction.
Tips
Wide-back fabrics (108") often need no seam. Press backing seams open. Square up after piecing.
Common mistakes
Buying exactly the top size with no overhang; forgetting selvage trim.
Piecing and pressing
Remove selvages before joining panels. A ½" seam is common for backing joins; press open to reduce bulk under quilting. Horizontal seams can be less visible on some beds; vertical seams may save fabric for certain dimensions—compare both with the calculator. Square the pieced backing before basting.
Limits and how to use the results
Estimates run only in your browser. Prefer a published pattern’s tested yardage when it conflicts with this planner. Density factors and assumptions are documented on the methodology page; legal terms cover planning-use limits.
FAQ
How much backing for a queen quilt?
Often 8–9 yards of 44" fabric pieced, or about 3 yards of 108" wide back—run your measurements here.
How much overhang do I need?
Longarm quilters often ask for 4" per side; domestic quilting may allow 2–3".