I have a slightly larger stuffsack for my sleeping bag and put my Prolite in the bag with the sleeping bag. You need fully deflate the pad. If it does not fit inside the bag it came in, then it is not fully deflated. It is tricky at first, but you soon will get the hang of it. If you kneel on the pad, be sure it is sitting on a smooth surface! I usually pack my sleeping bag and pad while inside the tent. I fold the pad with valve open, then sit on it all until it is squished, then tighten the valve.