Truth: If you quilt, you need math. Calculating yardages for borders, backs and bindings is part of the craft, whether you're making the best use of the fabric you have or deciding how much to buy.
Most quilt patterns tell you how much yardage you need, but when sewing your own projects you'll need to do a few calculations of your own.
Okay: You do the math!
1. Measure your completed quilt center; the left and right borders will be cut to the length of the quilt center. For a 40-by-50-inch quilt center, you'll need two pieces of fabric that are your width of choice by 50-inches long.
If you want 5-inch borders, for instance, cut three strips of fabric that are 5-inches wide by the width of your fabric. Piece with a diagonal seam, then cut two 50-inch-long pieces. Add your right and left borders to the quilt center.
2. Now measure the width of your quilt again to determine the length of the top and bottom borders. In this example, the quilt center measures 49-by-50 inches.
3. Add your top and bottom borders. Again, cut three strips that are 5-inches wide by the width of your fabric. Piece with a diagonal seam, then cut two 49-inch-long pieces.
After sewing these top and bottom border strips, your quilt will measure 49-by-59 inches. In total, you used six strips, each 5-inches wide by the width of your fabric. Since your strips are 5-inches wide, you used a total of 30 inches of fabric, or ⅞ yard.
With your borders added, you now have the measurements you'll need to figure yardage for your backing and binding.
For backings, you’ll need to remember to add 4 inches to each side measurement of your completed quilt top.
For the quilt in the example above, the backing should be 57-by-67 inches.
1. Cut two pieces of fabric that are 57 inches by the width of the fabric. Adding 57 inches and 57 inches gives you a total of 114 inches, or 3¼ yards of fabric.
2. Sew the two 57-inch-long pieces together along the 57-inch side.
3. Trim the length to 67 inches after sewing this seam.
1. For bindings made from width-of-fabric strips, add the measurements of all four sides of your quilt; then add 12 inches for seams, corners and finishing.
2. After you have your total measurement, divide by 42 inches to determine the number of strips you’ll need.
For example, if you have a finished 50-by-60-inch lap quilt, you’ll calculate 50 plus 50 plus 60 plus 60 plus 12, to equal 232 total inches of required binding. Six strips of fabric (6 x 2½ inches equals 15 inches or ½ yard) will give you about 252 inches of sewn binding, leaving you with a small amount of leftover binding.
Note: For scrappy bindings, remember that because you're using so many seam allowances to join smaller strips of fabric, you'll need quite a bit extra. For diagonally pieced scrappy bindings, count on at least 4 inches of each strip being taken up in the seams. So if you are using 10-inch strips for your scrappy binding, only about 6 inches of each strip will count toward your finished length of binding.