Quilt backing and batting calculator
Enter the size of your finished quilt top, in inches or metric. You'll get the backing fabric to buy and the batting size.
Backing
4 yards
Batting
68 in × 80 in
How the math works
- The backing is the quilt top plus the extra you choose on every side.
- Quilting cotton gives about 40 usable inches (102 cm) once the selvages are trimmed, so bigger backings are sewn from pieces. The calculator tries the seams both ways and picks the one that uses less fabric.
- Backing is rounded up to the next quarter yard, or the next 10 cm.
Want the step-by-step version? Read how much fabric for quilt backing and binding.
Questions quilters ask
How much extra backing do I need?
Allow 4 inches (10 cm) on every side. If a longarm quilter is finishing your quilt, ask them: many want 4 to 6 inches per side.
Why does the calculator turn my seams sideways?
Running the backing seam across the quilt instead of up it often needs less fabric. The calculator works out both and shows whichever uses less. Longarm quilters usually prefer horizontal seams too.
How big should the batting be?
The same size as the backing, so there's batting under every bit of the quilt top while it's quilted.
Is wide backing worth it?
Wide backing is about 108 inches (274 cm) wide, so most quilts need just one piece with no seams. It costs more per yard but you buy less, and there's no seam to sew.