I use mine and the size requirement for me is big enough to curl up in while making like a couch potato. :lol: So I guess that would be about the same as a twin size quilt?? Like everyone else, I like it long enough that it will cover me while in my favorite position (prone) and wide enough to cover me side to side. And I use them and when it gets REALLY cold they sometimes migrate up to the bed as an additional layer.