Here are a couple of tips for sizing:
For neck and chest, please allow sufficient room to slip two fingers (stacked on top of each other) between the measuring tape and the dog’s neck or chest.
A snug fit is what you are aiming for - just make sure it is not too tight or chokes your pet.
Order the next size up if your dog falls between measurements.
The hoodies are stretchy material. If you are between sizes, size up for a loose fit or size down for a tighter fit.