King quilts are the one size where 108 inch backing needs a moment of arithmetic before you order. Most king tops fit on a single width. Some do not. Here is how to tell which you have.
King quilt and backing measurements
A standard king mattress is 76 by 80 inches and a California king is 72 by 84. Finished king quilt tops vary more than any other size, usually between about 94 by 104 and 108 by 108 inches.
| Finished top | Backing for home quilting (4 in margin) | Order from 108 in fabric |
|---|---|---|
| 94 x 104 in | 102 x 112 in | 3.25 yards |
| 100 x 100 in | 108 x 108 in | 3 yards, no margin to spare |
| 104 x 104 in | 112 x 112 in | exceeds the 108 in width, see below |
| 108 x 108 in | 116 x 116 in | exceeds the 108 in width, see below |
The 108 inch limit
This is the part worth understanding before you buy. The fabric is 108 inches wide, so no single cut can produce a backing dimension larger than 108 inches, however much length you order. Both of your backing measurements have to be checked: one of them must come in under 108 inches for a single width to work.
If your top is 94 by 104 inches, the backing needs to be 102 by 112. The 102 inch dimension fits inside the 108 inch width, and 3.25 yards covers the 112 inch dimension. One piece, no seam.
If your top is 104 by 104 inches or larger, both backing dimensions exceed 108 inches. At that point you have three options: piece two lengths of 108 inch fabric together, use a 120 inch backing, or reduce the margin, which we would not recommend if a longarm quilter is finishing it.
If you need to piece
Pieced backs are normal on very large quilts and there is no reason to avoid one. Run the seam horizontally rather than down the centre so it sits across the quilt instead of along the fold line, press it open rather than to one side to reduce the ridge, and tell your longarm quilter it is there before they load it.
Which backing suits a king quilt
At this scale a textured blender is the safer choice: marble tonals and grunge absorb quilting lines across a large area far better than a flat solid does. If the back will be seen, the digitally printed range prints across the full width and gives you a genuine second side.
Browse all 108 inch quilt backing fabric, or by colour: blue, green, red and pink, purple, black and gray, brown, off white and cream.
Send your finished measurements to sharon@108quiltbackings.com if you would like us to check the yardage before you order.
See also: how much quilt backing do I need and queen size quilt backing.