It depends what you are using them on. I have a 13 and a 17. The 13 just barely fits in the 18.5 where you can close the lid and the 17 fits well in the 22.5 The thing is, you really don't need to be able to close the lid. I really like having two because I like making deep dish pizzas in the 13 inch pan and breakfasts and paella in the larger one. I am also planning on setting up my 13 for use on my smokey joe elevated just above the top edge.