sorry, there is no way to do this. I learned this in my "yout" for knitting. You have to buy enough, for me, that means adding 1/2-1 yard. I'd rather have way too much than an inch too little. you'd be better off doing what Dunster suggested, using a different fabric for the border or such. There is so much fabric manufactured that very little lasts longer than a season. it's just the way it is, now.