Help with backing calculations
 

I am finishing a top that is 48x57. I found a fabric in my stash that is in two pieces, one piece is 2 yards, the other is 1 yard. I only need 2 0r 3 inches extra on each side. Can someone please help me figure out if I can use this fabric for the backing and if so, how would I do that. I am sure that some of you math experts here can help me. If not I do have another fabric that will easily fit. Any help will be appreciated! I do have the Robert Kaufman app that calculates yardage but I don't think it tells me the info I need for this.

Is the backing fabric directional? Are you quilting it or sending to LA?

Rhonda K- the fabric is not directional and I will quilt on my dsm, so I don't need more than 2 or 3 inches overage.

I would cut the shorter piece in half lengthwise and sew the shorter ends together. Then sew this to the 2 yard piece. Might not be the preferred way for some but I make due with what I have

48x57 = 2,736 sq inches in your pieced top
48+5=53 57+5=62
53x62=3,286 sq inches with 2.5" added for each side
3 yards = 3x36= 108 inches length
108x42= 4,536 sq inches of backing material

The fun thing is now, how to cut the fabric. I go simplistic. I would use the 2 yard long, 72" piece lengthwise across the 62 inch. (You should have an extra 10 inches.) Then I would take the 1 yard piece and cut it in half, as in 2 pieces that are 36" long x 22". Sew the 36" length together, and now you have a piece that is almost 2 yards long x 22" wide to sew to the original 2 yard piece. After sewing this new pieced backing fabric should be about 71" x 64". Now you can trim to the size you want to cover your pieced top which is 53"x62" which includes the 2.5" on each side.

Check my math carefully before you cut. I'm a quilter and I am not perfect.

You could get creative with the second fabric and incorporate it into a step pattern on the back.

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Ooo! I love creative backing!

I would skip the math because... hello? It’s math! I’d keep the 2 yd piece intact but cut down by “eyeballing” the amount you need with overhang plus a little for shrinkage that happens when you quilt.

I’d cut the 1 yd piece in half lengthwise and sew the short ends together. Then I’d sew a contrasting strip between them for visual interest, even though it’s not mathematically necessary. Then trim around the perimeter, leaving yourself the needed overhang for sandwiching.

Take my advice with a very big grain of sAlt. i’d rather waste a little fabric than a lot of time doing math! LOL

What a pretty idea! Thanks for showing :thumbup:

Thanks ladies for the info. I ended up using a 3 1/2 yd piece that I had originally purchased for this little quilt. It works fine. I just got distracted by the other pieces but couldn't really get into making it work. Thanks again for your help. Zozee, you made me laugh! My thought exactly- math, no thanks. Gives me a headache!

Mywebquilter.com is the best free online quilt calculator I have ever found . Backing , borders , sashings , binding , and many other calculations such as square in a square , on point settings, quilt blocks library ; it's a world of information .

I rarely use a 'regular' backing. I add bits and blocks or strips, just something different. Depending on the fabric you have, with your pieces the simplest way would be to cut the 2 yard piece down the middle, take the one yard piece, cut it and resew it to make a long piece and add it to the middle of the backing. Another option (but more sewing) would be to cut the 2 yard piece into 3rds and insert a resewn long bit on each side creating 5 long bits. a very wise designer told me to not try to make too little look like a single piece. It will always look like you ran short. She told me to play up the lack of fabric to create a whole new look. This has worked for me for many, many years.

Glad you got it figured out, Suern3.

I took college level trig when I was a senior in high school. In college I did class after class of statistics, doing it by hand even though computers had been invented by then! I worked with engineers, I did payroll, I did all sorts of math in my head.

Then when I was about 40 I started losing my math abilities. Don't know if it is aging, my medications, or what but stuff that used to be super easy and done in my head I can barely do on paper any more. I'm still pretty darn good with a calculator. But at 60, I am definitely getting more and more math challenged and I'm doing more and more by charging ahead and seeing what comes out.

While I prefer extra wide fabric for backs, I can't always afford it. For whatever reasons I am fundamentally unable to make a quilt be less than a width of fabric, just can't do it... even if I can, then the back I want to use is only 40 usable inches or whatever and not the full 44" I need.

As time has gone on, I do more and more piecing of my backs rather than less because I like it and it allows me to use fabrics I collected for the top but didn't use there, or a good place for large scale prints. For the same reason I typically use a slightly wider than standard binding and sometimes even piece the binding, it's one last place I can add fabrics!

I can picture this! (cutting the 2 yards in half and adding the other piece to the middle). I did finish the quilt sandwich today though, so will have to be happy with the backing I used. Thanks for your input.

Iceblossom, you surely have a lot of math experience! I like to joke that my two older brothers used up all the math genes in our family and left none for me:) They both worked in math heavy careers. I, of course, needed to use math in my nursing career and I was able to do that just fine. I think I was so concerned about it that I kind of over-compensated. But since I retired I seem to have happily let my math go.:)

There is s method developed by John Flynn where you take backing fabric that is not wide enough and cut it diagionally and slide one side down until you have the width needed. It works. It is on his web site.