🧵 Binding Length Calculator

Enter your quilt's perimeter and the usable width of fabric you'll cut binding strips from (fabric width minus selvage) to see the total binding length needed and how many strips to cut.

Quilt perimeter (in)

Corner/join allowance (in)

Usable fabric width per strip (in)

Perimeter plus slack, divided by strip length

The calculator adds the corner allowance to the perimeter, divides by the usable width, and rounds up to a whole strip.

binding length = perimeter + corner allowance
strips         = ceiling(binding length / usable width)

defaults: 280 in perimeter, 10 in allowance, 40 in usable

Those defaults describe a 60 × 80 in quilt: 280 in of perimeter plus 10 in gives 290, and 290 / 40 is 7.25, rounded up to 8 strips. Two constants carry the answer. 40 in usable assumes cotton sold at 42-44 in with the selvages trimmed and the cut squared; 10 in of allowance assumes four mitred corners plus the closing join.

From strips to fabric on the bolt

The tool counts strips, not yardage - it never asks how wide you cut them. Multiply the count by your strip width and divide by 36:

Quilt	Perimeter	Strips
Crib 36 × 52	176 in	5
Throw 50 × 60	220 in	6
Twin 60 × 80	280 in	8
Queen 90 × 108	396 in	11
King 108 × 108	432 in	12

Eight strips cut 2½ in wide need 20 in down the fabric, so 5/8 yd leaves a little over.

Measure your own fabric first. Usable width varies by mill and shrinks in a prewash: 38 in instead of 40 is still 8 strips here, but on a queen it is the difference between 11 and 12. These figures also assume straight-grain strips cut selvage to selvage - bias binding comes off the diagonal of a square, and this arithmetic does not describe it.

Frequently asked questions

How much binding do I need for a 60 x 80 inch quilt?

290 in of binding: 280 in of perimeter plus the 10 in allowance, which comes from 8 strips cut across a 40 in usable width.

How wide should I cut binding strips?

The calculator does not ask, because the count is the same either way. Double-fold binding is commonly cut between 2 and 2½ in; wider strips use more yardage, not more strips.

Why does it assume 40 inches when my fabric is 44?

Because the selvages are unusable and the cut end is rarely square. Trimming both edges typically leaves around 40 in, and the box is editable if yours measures otherwise.