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How Much Fabric for a King Quilt Backing?

Last updated Researched from specs, manuals and owner reviews We earn from qualifying purchases
Quick answer

For a 106 x 95 inch king quilt with 4 inches extra per side, buy 8 5/8 yards of 42 inch quilting cotton (3 panels, vertical seams) or 3 1/4 yards of 108 inch wide backing. If your longarmer asks for 6 inches per side, plan 9 or 6 5/8 yards.

This page works out backing for a king quilt top of 106 x 95 inches, the typical size in our quilt size chart. If your top is a different size, the quilt backing calculator runs the same math for any measurement.

How much king backing do you need for each overage?

Overage is the extra backing added to every side. Home quilters often use 2 to 4 inches, while longarm quilters typically want 4 to 6 inches so the frame can clamp the fabric.

King backing yardage by overage (40 in usable width)
Extra per sideBacking size (in)42 in, vertical42 in, horizontal108 in wide
2 in110 x 99 8 1/4 yd (3) 9 1/4 yd (3) 3 1/8 yd
4 in114 x 103 8 5/8 yd (3) 9 1/2 yd (3) 3 1/4 yd
6 in118 x 107 9 yd (3) 9 7/8 yd (3) 6 5/8 yd
8 in122 x 111 12 3/8 yd (4) 10 1/4 yd (3) 6 7/8 yd

How do you piece a backing for a king quilt?

With 4 inches per side, the cheapest layout for standard cotton is vertical seams. Here is the cutting plan.

  1. Buy 8 5/8 yards of 42 to 45 inch quilting cotton, in one continuous length if possible.
  2. Cut 3 panels, each 103 inches long.
  3. Trim the selvages from both long edges of every panel.
  4. Sew the panels together along the long edges with a 1/2 inch seam and press the seams open. The finished piece needs to be at least 114 inches across, so the last panel only needs to be about 34 inches wide and you can trim the extra.
  5. Square the backing to about 114 x 103 inches and mark the center of each edge.

Seams and longarms

Many longarm quilters prefer backing seams that run horizontally, parallel to the frame rollers, because the fabric rolls more evenly. If yardage is close, ask which way your quilter wants the seams.

Does fabric width change the king backing yardage?

Quilting cotton is sold as 42 to 45 inches wide, but the usable width after trimming selvages, and after prewashing, can be 38 to 44 inches. For some sizes that difference adds a whole panel.

King backing by usable fabric width (4 in overage)
Usable widthBest layoutYards
38 in3 panels, vertical seams8 5/8 yd
40 in3 panels, vertical seams8 5/8 yd
42 in3 panels, vertical seams8 5/8 yd
44 in3 panels, vertical seams8 5/8 yd

What if your king quilt is bedspread size?

A bedspread-style king quilt that reaches toward the floor (a 22 inch drop plus a 12 inch pillow tuck) finishes near 120 x 114 inches. Its backing needs 13 5/8 yards of 42 inch cotton (4 panels) or 7 1/8 yards of 108 inch wide backing with 1 seam.

Longarms and frames for king-size quilts

King quilts are heavy. A midarm, sit-down longarm or frame system lets the machine do the work instead of your shoulders.

Prices change often, so confirm on Amazon. As an Amazon Associate we earn from qualifying purchases.

Is it cheaper to send a king quilt to a longarmer or quilt it yourself?

Longarm services usually price by the square inch of the top. A king top is 10,070 square inches, so even a modest edge-to-edge rate adds up across several quilts a year. Run your own numbers in the longarm cost calculator before deciding whether a sit-down longarm or frame belongs in your sewing room.

Safety note: Rotary cutters are extremely sharp: close the blade guard whenever you set one down and cut away from your body.

Frequently asked questions

How many yards of fabric do I need for a king quilt back?

A king quilt of 106 x 95 inches needs a 114 x 103 inch backing with 4 inches extra per side. In standard 42 inch cotton with about 40 inches usable, that is 8 5/8 yards cut into 3 panels. In 108 inch wide backing it is 3 1/4 yards. Buy an extra 1/4 yard if you plan to prewash or match a large print.

Should I use wide backing for a king quilt?

Yes, for most quilters. Pieced from 42 inch cotton, a king back needs 3 panels and 2 long seams. A single 3 1/4 yard length of 108 inch wide backing has no seams, which longarmers prefer, and is often cheaper per square inch.

How much extra backing does a longarm quilter need for a king quilt?

Most longarm services ask for 4 to 6 inches extra on every side, and a few ask for 8. At 6 inches per side, the king backing grows to 118 x 107 inches, which is 9 yards of 42 inch cotton or 6 5/8 yards of wide backing. Ask before you cut, because a short backing is the most common reason a quilt is sent back.

How do I cut and sew a pieced king quilt backing?

Cut 3 panels of 42 inch cotton, each 103 inches long. Trim off the selvages, since they shrink differently. Sew the panels along their long edges with a 1/2 inch seam, press the seams open, then trim the pieced back to about 114 x 103 inches. Mark the center of each side to help line it up with the top.

Does washing fabric change how much backing I need?

Yes. Prewashed quilting cotton can lose 1 to 2 inches of width and several inches of length per yard, and trimmed selvages take another inch. If you prewash, plan with 38 to 40 inches of usable width. The usable width table on this page shows how the yardage changes, and a small change can add a whole panel on bigger quilts.

How we research: we compare manufacturer specifications, owner manuals, published standards and recurring themes in verified owner reviews. We do not test products in person, and this is researched guidance, not professional advice. Follow your machine manual and pattern, and take care with rotary cutters, hot irons and needles. As an Amazon Associate we earn from qualifying purchases.