It is recommended that you measure the length of a dog's back and chest,
back length do not include the length of the neck and tail,
chest circumference is the forelimb part of the perimeter of the widest.
In the process of your choose and purchase, remind you note:
pet clothing on the back should not be longer than the pet's actual back length,
because dogs often sit down, long clothes is easy to dirty,
and clothes chest should be greater than the actual chest length of dog,
it is convenient for its activities.
Please consider 0.5 inch error.