5 quick steps to calculate yardage for quilt backing [3 styles]

Yesterday on QUILTsocial I showed you how to make a floating pieced block border using my Brother NQ900 sewing machine. I now have a completed quilt top, so I need to figure out what to do about my backing fabric.

Lots of quilters buy wide backs of quilting fabric that are 104” to 120” wide to put on the back of their quilts. But if you can’t find one you like or have fabrics in your stash you want to use up, you probably need to piece your backing.

Here’s how to figure out how much fabric you need for the back of your quilt.

Step 1 Measure your quilt.

Easy-peasy! Just measure the length and width of your quilt and add about 6” to 8” to both of these measurements. My quilt top is 42” x 64” so I need a backing that’s at least 48” x 72”. This is an awkward size because it’s just a bit wider than the width of most quilting fabric, so I need to piece my backing.

Step 2 Decide if you need to piece horizontally or vertically.

This step is probably where most quilters go off the rails, but you really don’t need to fret! Just look at the size of your quilt and decide which side of the quilt can be most closely matched by a multiple of the width of fabric. For this measurement, we as pattern designers always assume the fabric is 40” wide – we do this because some quilters will prewash (and shrink) their fabric before sewing. So, for my quilt, the length is 72” which is closer to 80” (2 x 40”) than my width (42”) is. So, if I piece my quilt horizontally, the back will look like this:

If your quilt top is longer than 80” and the width is 65” to 70”, then you’re probably best to piece your backing vertically (so the seam goes down the middle from the top to the bottom. The quilt backing will look something like this:

You can also piece three sections together to make a backing that’s wide enough for a king-sized quilt.

One of the most fun ways you can make a backing is to use left-over blocks or fabric scraps from the front of the quilt to make a backing that matches. The sky’s the limit when it comes to how you can piece this backing. If you have a piece of backing fabric that’s long enough for your quilt, but is just a bit too narrow, you can use this method easily by splitting the fabric in half lengthwise and then making a pieced strip that goes down the middle of the quilt back like in this diagram:

Since I have a nice large piece of the yellow word fabric and large blocks of the fabrics that I used to make my flying geese, I’m using this method to make my backing.

Step 3 Calculate yardage.

Now that you decided how to piece your quilt, you need to calculate the amount of fabric required. If you’re piecing horizontally, you need two fabric sections that are 6” to 8” longer than the width of your quilt. So, a quilt that is 64” wide needs two sections that are about 70” long. The total amount of yardage is 140” (70” x 2). Divide this number by 39 to get the number of meters needed:140/39 = 3.6m. To get the number of yards needed divide this number by 36: 140/36 = 3.9yds which is approximately 3⅞yd.

Step 4 Cut fabrics.

Cut your backing fabric into sections in the lengths needed. Trim one selvedge edge off each section. If you have directional fabric, make sure to cut the correct edges off so when you sew the fabrics together, they’ll both be going in the right direction.

If you’re piecing two sections vertically, cut them 6” to 8” longer than your quilt and remove one selvedge from each. If you’re piecing 3 sections together, cut both selvedge edges off the middle section.

You may be asking “Why do you cut off the selvedge?”. We do this because the selvedge edge does not stretch like the main fabric and is more tightly woven than the rest of the fabric making it harder to quilt through, and it won’t shrink the same when washed.

Step 5 Sew and press.

I’m using some of the leftover fabric from my flying geese blocks to make a strip to go down the center of my backing with my Brother NQ900 sewing machine. For this method, trim the blocks so they’re all the same width – don’t worry about what length they are. Sew the rectangles of fabric together using a ¼” seam, and then press all the seams open. By pressing the seams in your backing open, you make the seams less bulky for quilting.

Once the center strip is long enough, sew the two long sections of the backing fabric to either side of your pieced strip. Sew the cut edge of the backing fabric to the pieced strip, not to the selvedge edge. And then press the seams open.

Here’s my finished backing. Now I’m all ready for quilting!!

Now that I’ve got my quilt top and backing made, I’m ready to layer them with my batting and start quilting with my Brother NQ900 sewing machine. I think simple lines that go from top to bottom are a quick and easy way to quilt the lap quilt on my home machine. Hopefully, my new puppy Piper will keep letting me have some uninterrupted quilting time and I’ll be able to get this quilt finished before the end of patio season!

See you next time!

This is part 5 of 5 in this series

Go back to part 4: 4 steps to adding a floating block border to your quilt top [easy tutorial]