Calculating Yardage

Yesterday we determined that we needed the following pieces to make the 12 blocks needed for the top.

  • Green: 12 – 4-1/2″ squares
  • Background: 48 – 2-1/2″ x 4-1/2″ rectangles
  • Background: 144 – 2-1/2″ squares
  • Blue: 96 – 2-1/2″ x 4-1/2″ rectangles
  • Blue: 144 – 2-1/2″ squares

This is a chart that I keep in the drawer of my computer.  It avoids having to calculate how many pieces we can get for a strip.  I base my calculations on having 40″ usable across the width of the fabric.  If your fabric is narrower or has a huge selvage, your numbers may be different.  Of course, if you’re working from scraps or fat quarters, these figures won’t help you but there are charts for using fat quarters.

The chart can be downloaded here.

On the example we’re using, we know that we need 12 – 4-1/2″ squares.  Look at the chart and see that we can get 8 – 4-1/2″ squares per strip across the width of the fabric.  Divide the number of squares needed (12) by the number you can get per strip (8) = 1.5 so I know I need to cut 2 strips that are 4-1/2″ wide.  Then I would cut each of those strips into 4-1/2″ squares so I would have the needed 12 – 4-1/2″ squares.  That means that from the green fabric, I would need 2 – 4-1/2″ strips, or 9″.

For the background, we need 48 – 2-1/2″ x 4-1/2″ rectangles.  We already know from above that we can get 8 – 4-1/2″ pieces from a strip so we would need to cut 6 – 2-1/2″ strips, and then cut those into 2-1/2″ x 4-1/2″ rectangles.  6 x 2-1/2″ = 15″.  Here, I would check to see if cutting the other direction would be more economical.  Suppose we cut our strips 4-1/2″ wide and then cut those into 2-1/2″ segments.  From the chart, we know that we can get 16 – 2-1/2″ pieces per strip.  48 divided by 16 = 3 so to use this method, we would cut 3 – 4-1/2″ strips and that would take 13-1/2″ of fabric, which is less than 15″ of fabric.  It isn’t a huge difference but if we needed 144 of these pieces, it would be a much larger difference.  Always figure both directions to see how you will get the most out of your fabric.  Let’s use the 13-1/2″ for this measurement.

We also need 144 – 2-1/2″ squares.  We know that we can get 16 – 2-1/2″ squares per strip so we divide the number of squares needed (144) by the number we get per strip (16) and find that we will need 9 strips, each cut 2-1/2″.  If the number had not been a whole number, round up.  Suppose the number had come out to be that we needed 9.3 strips.  Figure on using 10 just to be safe.  It may be that you’ll have a little left over from the strips used to cut the 2-1/2″ x 4-1/2″ rectangles but always be sure to err on the side of more rather than less.  So, we need 9 – 2-1/2″ strips so that’s 22-1/2″  (9 x 2-1/2 = 22-1/2).  For the background, we need 22-1/2″ plus 13-1/2″ or, a total of 36″.

For the blue, we need the same number of squares as for the background so we need 22-1/2″ for those.  We also need 96 – 2-1/2″ x 4-1/2″ rectangles.  We would need 12 – 2-1/2″ strips cut into 96 rectangles so we need 30 more inches for a total of 52-1/2″.

  • Green – 9″
  • Background – 36″
  • Blue – 52″

Not that quilters are trying to get the exact amount of fabric needed . . ever . . but what if you found the perfect fabric and there was just barely enough left on the bolt.  We need to always know the minimum that we have to have.  If you wash your fabric (I do) before using, you need to allow for a bit of shrinkage.  Most fabrics need to be straightened before cutting and sometimes after cutting a few strips, we need to straighten again.  AQS asks the authors to figure on 105% of the fabric needed, plus a few inches for shrinkage.  If my pattern needs exactly 36″, that would be 38″ plus maybe 3 – 4″ for shrinkage, so that comes to about 42″.  1-1/8 yards would give me 40-1/2″.  1-1/4 yard would give me 45″ and that’s probably the least I would buy.  I’ve been known to accident cut a strip wrong . . instead of cutting a 2-1/2″ strip, I might cut one 2-1/4″ or even cut it 2-3/4″ which I could cut down but that wasted some of the yardage I needed.

For the example we’re using, if I were writing this as a pattern, I would probably give the following yardage requirements:

  • Green – 3/8 yard
  • Background – 1-1/4 yard
  • Blue – 1-5/8 yard

And, if I were looking at this pattern and wanting to make this quilt, I would probably buy the following amounts:

  • Green – 3/8 yard
  • Background – 1-3/8 yards
  • Blue – 1-3/4 yards

The more fabric you’re buying, the more wiggle room that 105% extra gives you.  When 36″ is needed, it gives you an extra 2″.  If 120″ were needed, it would give you an extra 6″.

Yardage requirements in patterns written for others to use are usually, or should be pretty close to exactly what is needed.  When I’m figuring yardage for a quilt I’m making for myself, I write down exactly how many inches of fabric is needed and then when I’m digging through the stash, I can measure the number of inches I have on hand and know if I have enough fabric plus wiggle room.  Suppose my design needs 83″.  That’s 2.30 yards so a pattern would probably say I needed 2-7/8 yards but that doesn’t tell me exactly how much fabric I can get by with if I’m trying to make something work.  That is why on some of my designs posted on the blog, you will see “2-7/8 yards or 83″ to be exact.”  That means . . you need 83″ if your fabric has already been washed, is square, will not need to be squared again and you make no mistakes.  But at least it gives you an idea and you know what you would be comfortable with, knowing exactly 83″ are needed.

Calculating yardage is not difficult and you can do it!


  1. 2

    Tracy says

    Did you know there is an iPhone app, called QuiltingCalc, for this. Its free at Robert Kaufman fabrics web site. Thanks for the chart, I like to have a hard copy for my sewing room too.

  2. 4

    Pratima says

    Thanks so much for this wonderful tutorial, Judy. You’ve broken down things to make the math seem so simple while figuring out the block construction. I am not so good with Maths. I have that free app by Robert koffman and used it to figure out yardage for borders on a quilt and it helped me a lot.