Guest Blog Post by author Laura Laing

When you’re a complete fabric junkie like I am, you’re always looking for a bargain.  Of course, my eye is drawn to gorgeous designer fabrics with really high thread count.  Swoon!  But the cost—well, that can bring on a real fainting spell.

That’s why I started out sewing with fat quarters.  I found fabrics that I loved—and could easily afford—and figured out really cool things I could make with them.  Little, zippered change purses, box-bags for balls of yarn and knitting needle rolls.  I sewed and sewed and sewed.  And I was very happy.

Until I started eyeing my bare windows and mismatched sofa and side chairs.  If I could make all of those little things, I could make big things—like curtains and slipcovers—too.  

But cotton fabrics are generally 40”, 54”, 60” or 72” wide.  And that meant I was buying a lot of fabric.  

That’s when I met decorator fabrics.  And then I found HarmonyArt.  These babies come in 110” widths—plenty wide for the 98” long drapes I had planned.  And you can’t deny that Harmony’s designs are gorgeous.  Perfect for curtains, tablecloths, slipcovers, and heck, if I quilted, even quilts!

The prices were much higher though. Compared to the $15-$20 per yard I was used to paying for designer cotton fabrics, 110”-wide fabrics were at least $25 per yard.  It was time to do a little math.

I wanted to dress three windows in my new living room.  I drew this sketch to figure out the math.

Yes, that’s coffee on the sketch. It was a Saturday morning, and I wasn’t quite awake yet. The little circle things are clip rings that I wanted to use to hold the curtains onto the rod.

With 110” of fabric, I could make do with one yard per panel.  (It’s not as wide as the experts recommend, but with the rich design, I decided it would look terrific.)  

2 panels per window
3 windows
1 yard of fabric per panel

2 x 3 = 6 panels
6 yards of fabric total


I chose the Evelyn design from HarmonyArt’s collection, 
which is $28.80 per yard at Stitch Simple.  

$28.80 x 6 yards = $172.80

(I’m ignoring the tax and shipping costs here—because I have to pay them no matter what width fabric I buy.)

How much of the 54”-wide fabric would I need to make the same curtains?  That’s going to require more math.

If I want each panel to be about 36” by 110” (before they’re sewn), I would to need about 3 yards per panel.  Here’s why:

• Because the fabric is only 54” wide, it won’t work having the selvages at the top and bottom of the curtain.  (There are other reasons for this, too, but we won’t go into that right now.) That means the selvages will have to go from side to side, and the length will be the yardage purchased.
• Since I want my unsewn panels to be 110” long, I divide 110 by 36 (the number of inches in a yard) to find 3 yards:

110” ÷ 36” ≈ 3 yards
(that wobbly, little equals sign means “approximately”)

So I’ll need 3 yards of fabric per panel. And I’ll have lots left over.  In fact for each panel, I’ll have a 3-yard strip of 18” wide fabric left over. 

54” – 36” = 18”

(I could sew up those leftover to make one panel, but let’s face it—that’s a lot of work, and it’s not as good looking.)

How much 54”-wide fabric will I need for all 6 panels?

6 panels x 3 yards = 18 yards

And let’s say I’ve found a great sale on the designer fabric I love—$14 per yard.  What’s the total cost?

$14 x 18 yards = $252

Yikes!  Even though the 110”-wide fabric is much more expensive per yard, I’ll be spending a lot more for the 54”-wide fabric.

$252 - $172.80 = $79.20

The lesson for me?  While the 110”-wide fabric is more than twice the cost per yard, it’s the better deal for this project.  The same could be true for slipcovers, skirts, pillows and yes, even quilting.  

It pays to do the math.  (See?  These are my new curtains!)

Thanks Laura!  Laura is the author of the fabulous book Math For Grownups.  She has a great companion blog dedicated to showing us ways math can be useful and handy.  You can check out her post from Monday which is an interview with yours truly.  If you check back on Friday (Nov. 18th) she will be posting a how-to about sewing the curtains above. Enjoy!