Bare with me a minute, I'm going to try and remeber what I learned on America Quilts Creatively, a while back on this, If I remeber correctly, the lady said to measure the width of the prarie point, then measure the side of the quilt, Divide the width of the prarie point in to the length(side) of the quilt, to get how many you need, You would have to do that for each side of your quilt. So it would come out evenly, This is where you may have to adjust the width of the prarie point so it would come out even, I'm pretty sure that is how it's done, Try it and see, and let me know, I'm just trying to help, Ex: Prarie Point 4"
one side of quilt 48"= 4 into 48= 12 Prarie points
Let me know. Becky