Please use the total length of your dog when ordering our dresses. Most of our dresses are adjustable in the chest and waist so it is often more important to have the correct length. If your dog’s Length size is more than two Chest sizes different, please select the size in between. For example, a dog with a chest measurement of 11” (XXS) and a length measurement of 10” (S) would need to order a size XS.