How Much Backing Do I Need for a Quilt?
How Much Backing Do I Need for a Quilt?
Quilt backing is the fabric that goes on the back of your quilt. It needs to be larger than the quilt top so there is enough extra fabric for quilting, trimming, and squaring up the finished quilt.
If you are sending your quilt to a longarm quilter, backing size is especially important. Most longarm quilters need extra backing around all four sides of the quilt so the quilt can be loaded properly on the frame.
How Much Extra Backing Should You Add?
A common recommendation is to add 4 inches of extra backing on each side of the quilt.
That means you add 8 inches to the quilt width and 8 inches to the quilt length.
For example, if your quilt top is 60 inches wide by 72 inches long, your backing should be at least:
60 + 8 = 68 inches wide
72 + 8 = 80 inches long
So for a 60 inch by 72 inch quilt, your backing should be at least 68 inches by 80 inches.
Quilt Backing Formula
Quilt width + extra on both sides = backing width
Quilt length + extra on both ends = backing length
If you are adding 4 inches on each side, the formula is:
Quilt width + 8 = backing width
Quilt length + 8 = backing length
Example
Let’s say your quilt top measures 80 inches wide by 90 inches long.
Add 4 inches to the left side and 4 inches to the right side:
80 + 8 = 88 inches wide
Add 4 inches to the top and 4 inches to the bottom:
90 + 8 = 98 inches long
Your quilt backing should be at least 88 inches by 98 inches.
Can Regular Quilting Cotton Be Used for Backing?
Yes. Regular quilting cotton is often about 42 to 44 inches wide before trimming off the selvage. After removing the selvage, many quilters use about 40 to 42 inches as the usable fabric width.
If your backing needs to be wider than the fabric, you will need to piece the backing together.
Common backing options include:
One-piece backing if the quilt is small enough
Seamed backing using regular quilting cotton
Wide backing fabric, often 108 inches wide
Diagonal pieced backing for some quilt sizes
Which Backing Seam Direction Is Best?
For longarm quilting, a horizontal seam is often preferred because it can load more smoothly on the frame. A vertical seam can still work, but it may depend on the quilt size, fabric, and how the backing is pieced.
When piecing backing, press the seam well and use a sturdy seam allowance. Always remove selvages from seams because selvage edges can shrink differently and may cause puckering.
Should I Buy 108-Inch Wide Backing?
Wide backing can be a great option, especially for larger quilts. It often avoids the need for piecing the backing, which saves time and keeps the back of the quilt cleaner.
A 108-inch wide backing fabric may work well for many throw, twin, full, queen, and some king-size quilts, depending on the finished quilt measurements and how much extra backing is needed.
Use Our Free Quilt Backing Calculator
To make the math easier, use our free Quilt Backing Calculator. Enter your quilt width, quilt length, extra backing amount, and fabric width, and the calculator will estimate the backing size and compare common backing options.
Open the free Quilt Backing Calculator here:
Need Help Finishing Your Quilt?
Country Farmhouse Quilting offers friendly longarm quilting services, and mail-in quilts are welcome. If you are not sure how large your backing should be, we are happy to help you plan before you send your quilt.
The usable fabric width is the detail that’s easy to overlook. For a smaller project such as Sewlore’s patchwork table-runner design, I’d check whether a single piece still works once the quilting allowance is included, rather than buying from the finished dimensions alone. Do you ask for the same extra margin on narrow runners as on larger quilts?