OK, math was never my thing. I have tried to do the 'ciphering' and my head is all jumbled up. This is only the third quilt that i have made and for the last two, I just had the long arm lady use her muslin for the backing, but on this one I found a companion fabric for $3.98 per yard at Hancock's of Paducah so I figured I can actually afford the extra money and have a matching back. My quilt is 92 x 80. How much do I need to buy for the backing? (the long arm lady likes to have some extra to work with also)

I have a quilt calculater app. on my ipod you just put in the measurement and it tells you how much fabric you need. I put in 80 X 90 and it says I need 8 1/2 yards for a crosswise backing (4" overhang, unpieced) Hope this helps. If you have an ipod the app is free.

I always buy a min. of 7 yards for backing. I buy it when it's on sale. I don't really care what color or print it is, I have a backing stash to match about any quilt. Any left over is added to my piecing stash. Here is a good way to piece backing:

http://www.reddawn.net/quilt/backings.htm

my longarm girl likes 3" extra on all 4 sides, that would put you at 6 yds. seamed down the center with 1 extra strip since fabric is 42-45" wide. I'll be doing a video on piecing backs here shortly

you should NEVER have just one seam running the length of your backing (top to bottom one seam) when this is loaded on the bars and rolled that center seam builds and builds extra layers and makes a large thick area, and the outside edges 'flop' making it difficult to quilt it without wrinkles. if you are only going to have one seam it should be horizontal so when loaded that seam runs along the bar evenly and does not build up all that extra bulk

I use the Quilt Calulator; I round up and add 10 total to the measurement of my quilts. exam: 53 x 72, I use 63 x 82. That gives me more than enough to piece my backing as needed, and as mentioned in previous post, all the extra goes into my stash:)

Good way to increase your stash when starting out. I also round up requirements posted in patterns. 1/2 yd, I buy 1 full yard. You know, if I make a cutting error I have it covered.

remember to allow for shrinkage - I've had fabric shrink over two inches in width - and up to two inches in length

I've found it helpful to draw things out on graph paper and then making my calculations from that.

If I was piecing "crosswise" - and only wanted two seams, I would also buy at least 8.75 yards of fabric (to allow for uneven ends, etc)

(92 for quilt + 8 inches for LAQ + 3 inches for shrinkage + 2 inches for wonky cut) for each length x 3 lengths.
105 x 3 = 315
315/36 = 8.75 yards


If I was willing to piece one section, then I think I could "get by" with 7-5/8 yards of fabric

Jeannie, which app are your using? I have one called Quilt Fab and it calculates to 6-3/4 yards using those measurements. Everyone's figures are closer to 8 yds. I'll have to check my settings and see why it's calculating so low.