Quilt Backing Calculator: The Ultimate Guide to Fabric Yardage
Calculating fabric for a quilt back can be trickier than the quilt top itself. You need to account for "overhang" for the longarm machine, match patterns, and decide between piecing vertically or horizontally. Our **Quilt Backing Calculator** simplifies this math, helping you buy exactly the right amount of yardage—whether you are using standard 44-inch cotton bolts or 108-inch wide backing fabric.
Why Use a Quilt Backing Calculator?
Guessing leads to waste or, worse, running short. This tool accounts for seam allowances (usually 0.5" for backs) and usable fabric width (selvage removal). It compares vertical vs. horizontal piecing to find the most economical cut.
Key Concepts in Quilt Backing
To get the most out of the **quilt yardage calculator**, understand these terms:
1. Overhang (The Extra Inches)
If you are sending your quilt to a longarm quilter, they typically require 4 to 5 inches of extra fabric on all four sides. This means if your quilt top is 60" x 80", your backing needs to be at least 68" x 88". Our calculator adds this automatically based on your input.
2. Vertical vs. Horizontal Piecing
- Vertical Seams: Fabric panels run top to bottom. Seams are vertical. This is the most common method as it follows the "grain" of the quilt top usually.
- Horizontal Seams: Fabric panels run side to side. This can sometimes save fabric yardage depending on dimensions, but the seam runs across the quilt horizontally.
3. Usable Width of Fabric (WOF)
A "44-inch" bolt of fabric usually only has about 40 to 42 inches of usable material once you cut off the selvages. This calculator assumes about 1-2 inches of loss to ensure you don't run short.
Standard Quilt Sizes & Backing Estimates
While custom measurements are best, here are general estimates used in our **quilt backing calculator** logic:
| Size | Approx. Dimensions | Est. Backing Yardage (44") |
|---|---|---|
| Baby | 36" x 52" | 1.5 - 2 Yards |
| Throw/Lap | 50" x 65" | 3.5 - 4 Yards |
| Twin | 70" x 90" | 5.5 - 6 Yards |
| Queen | 90" x 108" | 7.5 - 8.5 Yards |
| King | 110" x 110" | 9.5 - 10 Yards |
How to Calculate Quilt Binding
Our tool includes a **quilt binding calculator** toggle. Here is the math:
- Perimeter: Calculate the total inches around the quilt:
(Width + Length) x 2. Add 10-12 inches for corners/joins. - Strips Needed: Divide the total perimeter by the usable width of fabric (usually 40-42"). Round up to the nearest whole number.
- Yardage: Multiply the number of strips by the strip width (e.g., 2.5") and divide by 36 to get yards.
FAQ
Should I wash my backing fabric?
Yes. Backing fabric (especially wide backs) can shrink significantly. Wash and dry it before piecing to prevent the quilt from distorting later.
What is a "Wide Back"?
Wide back fabric (108" wide) is designed specifically for quilts. It eliminates the need for seams for quilts up to Queen/King size. It is often cheaper than buying multiple yards of 44" fabric.
Disclaimer: This calculator adds a small safety margin. Always double-check measurements before cutting. Fabric patterns requiring matching will need extra yardage not accounted for here.