Learning how to make continuous bias binding begins with determining how much fabric you'll need.
The calculations are easy. First we determine the total length of binding needed and then the cut width of strips. Next, we measure to find the usable width of your binding fabric.
That's it for the calculations!
Using our Bias Binding Yield Charts is the final step to decide how big a rectangle of fabric you'll need. Let's get started.
Calculate the Total Length of Binding Needed
Measure the distance around your quilt and add 12". This extra is for mitering corners and joining the ends of our binding.
Decide what the finished binding width should be. Now use this simple formula to find the cut width of your binding strips:
4 x Finished Binding Width plus 2 x Seam Allowance = Cut Width of Strips
You may need to add an extra 1/4" to this cut width measurement depending on the thickness of your batting.
Now a good binding is a full binding where the quilt sandwich fills the binding to its edge. So you'll square up your quilt accordingly.
EXAMPLE 1: A finished 1/4" binding
Square up the quilt top even with the edges of the quilt top, fine tuning if necessary.
4 x 1/4" plus 2 x 1/4" equals binding strips cut 1-1/2" wide
EXAMPLE 2: A finished 1/2" binding.
Baste the edges of the quilt top with a scant 1/4" from the edge of the quilt. Now square up the quilt sandwich by trimming away the batting and backing a 1/4" past the edge of the quilt top, again, fine tuning as necessary.
Option 1: If you plan to sew the binding to the quilt by lining up the cut edges of the binding with the edges of the quilt top, the calculations are as follows:
2 x 1/4" plus 4 x 1/2" plus 1/4" equals bias strips cut 2-3/4" wide
Option 2: If you plan to sew the binding to the quilt by lining up the cut edges of the binding with the cut edges of the quilt top, then the calculations are:
2 x 1/2" plus 4 x 1/2" plus 1/4" equals bias strips cut 3-1/4" wide
Now Use the Bias Binding Yield Charts
Now that you know the width to your strips and the total length of continuous binding you'll needed, you can use a simple chart. We've done the math for you!
Most methods for making continuous binding use a square of fabric. I don't buy squares of fabric, but I do buy yardage and fat quarters.
So we create continuous binding out of rectangles of fabric that use the width of the fabric as purchased from the quilt store.
Remember, when using the Binding Yields charts below, that measurements are based on squared up rectangles of fabric that you have removed the seam allowances from.
The long edges of the rectangles are sewn together to create a fabric tube. This technique only works if you start with a true rectangle where both sets of opposite sides are parallel to each other.
If you purchase a 1/4 yard of fabric and have to cut it down to square it up, the binding it yields will be somewhat less than that listed in the table.
EXAMPLE: Our 60" x 80" quilt needs 292" of a 1/4" finished binding. Binding strips will be cut 1-1/2" wide.
In the left column, "Cut Width of Binding Strips, find 1-1/2". Moving to the right, we see that a 1/4 yard cut yields 216", not enough. We would need a 3/8 yard cut of a 40" wide usable width of fabric to make the needed continuous bias binding.
Cut Width of Binding Strips
Bias Binding Yields for Fabric Cuts of... (Assumes a usable fabric width of 40" after the selvedges are removed)
1/4 yd by 40"
3/8 yd by 40"
1/2 yd by 40"
5/8 yd by 40"
3/4 yd by 40"
7/8 yd by 40"
1 yd by 40"
1-1/2"
216"
330"
445"
560"
674"
789"
903"
1-3/4"
180"
275"
371"
466"
562"
657"
753"
1-7/8"
168"
257"
346"
435"
524"
613"
702"
2"
156"
239"
321"
404"
487"
569"
652"
2-1/4"
144"
220"
296"
373"
449"
526"
602"
2-1/2"
132"
202"
272"
342"
412"
482"
552"
2-3/4"
120"
183"
247"
311"
374"
438"
502"
3"
108"
165"
222"
280"
337"
394"
451"
3-1/4"
96"
147"
197"
248"
299"
350"
401"
3-1/2"
84"
128"
173"
217"
262"
306"
351"
Since fat quarters are so readily available, we've calculated binding yields for them, too.
Cut Width of Binding Strips
Bias Binding Yields for a Fat Quarter (Assumes an 18" x 21" usable rectangle after removing the selvedge)