Quilt binding: strips, joins and extra length

Binding goes around the whole quilt, so its length starts from the perimeter: twice the width plus twice the length. Guides add ten to twelve inches for turning the four corners and for joining the two ends.

The strips are cut across the fabric, so each one is as long as the usable width, about forty inches. Printed charts divide the binding length by that width and round up. That leaves out the joins. Strips are usually joined on the diagonal, laid at a right angle and sewn corner to corner, because a slanted seam spreads the bulk along the binding; the overlap uses up about one strip width of length at every join. A straight join uses only its two seam allowances.

So the calculator looks for the smallest number of strips whose total length, less what the joins use up, reaches around the quilt. For most sizes the answer is the same as the chart; near a boundary it is one strip more, which is the strip that would otherwise be missing at the last corner. The second chart below shows where.

The fabric the strips take up is the number of strips times their cut width, rounded up to the step the shop cuts in. Two and a half inches is the usual cut width for double-fold binding.

Chart: binding strips by quilt length and width, with diagonal joins

Each cell is the number of strips for the quilt length in its row and the width in its column: strips two and a half inches wide, forty inches of usable width, ten inches extra and diagonal joins.

	Quilt width
Quilt length	40 in	50 in	60 in	70 in	80 in	90 in	100 in
40 in	5 pcs	5 pcs	6 pcs	7 pcs	7 pcs	8 pcs	8 pcs
50 in	5 pcs	6 pcs	7 pcs	7 pcs	8 pcs	8 pcs	9 pcs
60 in	6 pcs	7 pcs	7 pcs	8 pcs	8 pcs	9 pcs	9 pcs
70 in	7 pcs	7 pcs	8 pcs	8 pcs	9 pcs	9 pcs	10 pcs
80 in	7 pcs	8 pcs	8 pcs	9 pcs	9 pcs	10 pcs	10 pcs
90 in	8 pcs	8 pcs	9 pcs	9 pcs	10 pcs	10 pcs	11 pcs
100 in	8 pcs	9 pcs	9 pcs	10 pcs	10 pcs	11 pcs	11 pcs
110 in	9 pcs	9 pcs	10 pcs	10 pcs	11 pcs	11 pcs	12 pcs

Work out your own numbers: Quilt binding calculator

Chart: binding strips for a quilt eighty inches wide, by quilt length and kind of join

The first column ignores the joins, as printed charts do. Where the diagonal column is higher, a chart would leave you one strip short.

	How the strips are joined
Quilt length	Ignore the joins, as charts do	Straight joins	Diagonal joins
60 in	8 pcs	8 pcs	8 pcs
70 in	8 pcs	8 pcs	9 pcs
80 in	9 pcs	9 pcs	9 pcs
90 in	9 pcs	9 pcs	10 pcs
100 in	10 pcs	10 pcs	10 pcs
110 in	10 pcs	10 pcs	11 pcs

Work out your own numbers: Quilt binding calculator

Used by

• Quilt binding calculatorBinding strips and fabric for a quilt of any size.

Sources

• Linda's: quilt binding size chart
• My Girlfriend's Quilt Shoppe: how to calculate quilt binding