Dog Breeds by average size and weight

Size Neck (inches) Chest (inches) Weight (lbs) Breed
Mini 7.8-8.7 9.8-11.8 <10 Chihuahua, Yorkshire Terrier, Pomeranian, Maltese
Small 7.8-9.4 11.4-14.1 8-17 Jack Russell Terrier, Pekingese, Maltipoo, King Charles Spaniel
Medium 9-11 13.8-16.5 15-35 Cocker Spaniel, Beagle, French Bulldog, Pembroke Welsh Corgi
Medium 11.8-13.4 18.1-20.9 30-65 Bulldog, Standard Poodle, Husky, Pitbull, Dalmatian
Large 17-18.9 29.9-33.1 45-85 Boxer, Labrador Retriever, Schnauzer, Basset Hound
Large 18.5-20.5 34.6-38.2 50-100 German Shepherd, Bull Terrier, Old English Sheepdog
X Large 20.5-24.4 36.2-39.4 75-140 Rottweiler, Great Pyrenees, Newfoundland
Huge 24.4-28 36.4-43.0 100-200 St. Bernard, Leonberger, Mastife, Great Dane

Your dog is too small You will have to try it on. Perfect fit - congrats!