Well, you've gotten a 1 a 2 a 3 and a 4. One will definately not be enough (unless you are just doing the very middle area with the strips and then adding in very wide borders), 2 will be pushing it, 3 CAN get you there, but 4 will definately be plenty. thats just my 2 cents :-), I've made a few myself and depending on what you do with borders will also be a factor in how many rolls you need.