Quilt Backing Calculator
Enter the size of your quilt top and the width of the backing fabric. You get the yardage, how many panels to cut, how long each one is, and which way to sew the seams.
Quilt Backing Calculator
Enter the finished quilt top size and your backing fabric width. The calculator adds the overhang, picks the seam direction that uses the least fabric, and tells you how to cut the panels.
Formula: backing = quilt + 2 × overhang; panels = backing width ÷ usable fabric width (rounded up); yardage = panels × panel length ÷ 36
Results
Backing Fabric
3 ⅞ yd (3.6 m)
Cut 2 pieces 68" long and sew them along the selvages (horizontal seams). Trim the seam allowance to ½".
- Backing Size
- 68" × 80"
- 173 × 203 cm
- 108" Wide Back Instead
- 2 yd (1.9 m)
- No seams.
- Batting
- 68" × 80"
- Packaged size that fits: Twin.
- Binding
- ½ yd (0.5 m)
- 7 strips × 2½" across 42" fabric.
Usable width is the labelled width minus 2" for selvages. Longarm quilters usually ask for 4" extra on every side; check with yours before cutting.
Turn a photo into a real pattern
Upload a photo or drawing and get an embroidery pattern for a quilt label or a memory block.
Open Embroidery GeneratorBacking Yardage Chart
With 4" extra on every side, seams placed to use the least fabric.
| Quilt | Top (in) | 42" fabric | Panels | 108" wide back |
|---|---|---|---|---|
| Baby / crib | 36 × 52 | 2 ½ yd | 2 × 44" (horizontal seams) | 1 ¼ yd |
| Lap / throw | 50 × 65 | 3 ¼ yd | 2 × 58" (horizontal seams) | 1 ⅝ yd |
| Twin | 63 × 97 | 5 ⅞ yd | 2 × 105" (vertical seams) | 2 yd |
| Twin XL | 63 × 102 | 6 yd | 3 × 71" (horizontal seams) | 3 ⅛ yd |
| Full / double | 78 × 97 | 7 ¼ yd | 3 × 86" (horizontal seams) | 2 ½ yd |
| Queen | 84 × 102 | 7 ¾ yd | 3 × 92" (horizontal seams) | 3 ⅛ yd |
| King | 100 × 102 | 9 yd | 3 × 108" (horizontal seams) | 6 yd |
| California king | 96 × 106 | 8 ¾ yd | 3 × 104" (horizontal seams) | 3 ¼ yd |
How Much Fabric Do You Need for a Quilt Back?
Add the overhang to both sides of the quilt top — usually 4" per side, so 8" to the width and 8" to the length. That is the backing size.
Divide the backing width by the usable width of your fabric (42" cotton gives about 40" after the selvages come off) and round up: that is how many panels you need if the seams run down the quilt. Each panel is as long as the backing. Then check the other direction — panels as long as the backing is wide — because turning the seams sideways often saves most of a yard.
Wide-back fabric (108") skips the seams on anything up to a king quilt. It costs more per yard but usually less per quilt once you count the extra yardage and time a pieced back takes.
Piecing the Back
Cut the selvages off before sewing — they shrink differently from the rest of the fabric and pucker after washing. Sew the panels with a ½" seam and press it open to spread the bulk.
For two panels, one centre seam is fine. Some quilters prefer to split the second panel in half and sew one half to each side so the seams sit symmetrically; the yardage is the same.
Quilt Backing FAQ
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