Use a tape measure to measure around your dog's neck. If you don't have a tape measure, use a string, then measure the string on a ruler. Don’t make it too tight or too loose. If your pet’s measurement is between two sizes, it’s best to round up—if your dog has a 16 ½” neck, round up to 17″. That way you will have room for pet growth or fur thickness.
Double check your measurements and also make sure you have chosen the correct range in the size option when ordering a collar. For instance, if your dog’s neck measures 17″, choose the collar size 16″-18″ in the drop-down menu. The tongue of the buckle will fit in the center of the 5 holes in the collar at 17".