Enter Quilt Backing Details
Example Data Table
| Quilt Size | Quilt Width | Quilt Height | Extra Per Side | Fabric Width | Typical Yardage |
|---|---|---|---|---|---|
| Throw | 60 in | 72 in | 4 in | 108 in | About 2.25 yd |
| Twin | 70 in | 90 in | 4 in | 108 in | About 3 yd |
| Queen | 90 in | 100 in | 4 in | 108 in | About 3.25 yd |
| King | 108 in | 108 in | 4 in | 108 in | May need piecing |
Formula Used
Backing width: quilt width + 2 × extra side allowance
Backing height: quilt height + 2 × extra side allowance
Shrinkage adjusted size: backing size × (1 + shrinkage ÷ 100) + square-up allowance
Usable fabric width: fabric width - 2 × seam allowance
Panels: ceiling(required backing span ÷ usable fabric width)
Yardage: (panel cut length × panels ÷ 36) × (1 + waste percent ÷ 100)
Rounded buying yardage: The calculator rounds up to the next quarter yard.
How to Use This Calculator
Enter the finished quilt width and height in inches. Add the extra backing needed on every side. Many longarm quilters ask for four inches per side. Set fabric width to 108 inches for standard wide quilt backing.
Add shrinkage if the fabric may be washed before quilting. Add square-up allowance when the backing edges are uneven. Choose auto layout when you want the calculator to compare vertical and horizontal panel plans. Press calculate to see yardage, seams, panels, and cost.
Complete Guide to 108 Inch Quilt Backing
Why Wide Backing Helps
Wide backing fabric can save time. A 108 inch bolt often covers many quilts without center seams. This makes loading easier. It also gives a cleaner back view. The calculator checks the real backing size first. It adds side allowance before any yardage is estimated.
Allow Room Around the Quilt
Backing should be larger than the quilt top. Extra space helps with basting, clamps, frames, and longarm loading. Four inches per side is common. Some quilters use more for large quilts. Small quilts may need less. Always follow your quilter’s rule before cutting.
Plan for Shrinkage
Cotton can shrink after washing. The shrinkage option adds a safety margin. This is useful when fabric is prewashed. It also helps when the backing has a loose weave. A small percentage can prevent a short backing. The calculator applies shrinkage to both width and height.
Understand Panel Direction
A quilt may need one panel or several panels. If the required size is wider than usable fabric width, seams are needed. Auto mode compares two directions. It then chooses the lower yardage. You can still force vertical or horizontal panels when grain, print direction, or design matters.
Estimate Buying Cost
The price field gives a quick budget. Yardage is rounded up to the next quarter yard. This matches many fabric shop cuts. Waste percentage covers trimming, squaring, and cutting errors. The final value is a planning estimate. Buy slightly more for directional prints or matching repeats.
FAQs
What is 108 quilt backing fabric?
It is extra wide fabric, usually 108 inches across. It is made for quilt backs and can reduce or remove pieced seams.
How much extra backing should I add?
Many quilters add four inches on every side. Longarm quilters may request more. Always check the quilting service instructions first.
Does this calculator include shrinkage?
Yes. Enter a shrinkage percentage. The tool increases both backing width and height before calculating panels and yardage.
Why does the calculator round yardage up?
Fabric is often sold in quarter-yard cuts. Rounding up also helps cover trimming, uneven edges, and small measuring errors.
When do I need more than one panel?
You need more panels when the required backing span is wider than the usable fabric width after seam allowances.
Can I use fabric wider than 108 inches?
Yes. Enter the actual fabric width. The calculator will use that width when estimating panels, seams, and yardage.
What does auto layout mean?
Auto layout compares vertical and horizontal panel plans. It selects the option with lower yardage based on your inputs.
Is the cost estimate exact?
No. It is a planning estimate. Store pricing, taxes, coupons, fabric repeats, and minimum cut rules may change the final cost.