Step 1: Measure around the lower part of your dog's neck.
Step 2: Measure around the upper part of your dog's chest.
Step 3: Measure or estimate your dog's weight.
Step 4: Compare values to our table. Some of your measurements may fall under two sizes. Follow these guidelines in that case:
If you’re in between sizes, for dogs that have a wide chest or shoulders, go UP one size.
If you’re in between sizes, for dogs that have a narrow chest or body, go DOWN one size.