For a proper fit measure around your dogs neck for a collar and for a harness measure around their chest and allow for a few fingers of play for comfort.

breed neck size (inches) weight (lbs.)
Afghan 16-22" 58-64 lbs.
Airdale 16-22" 42-46 lbs.
Australian Shepherd 16-22" 35-75 lbs.
Basset Hound 16-22" 40-60 lbs.
Beagle 12-18" 18-30 lbs.
Bichon Frise 14-18" 10-14 lbs.
Bloodhound 22-28" 88-105 lbs.
Border Collie 14-18" 30-45 lbs.
Boston Terrier 12-18" 10-25 lbs.
Boxer 16-22" 55-75 lbs.
Britany 14-16" 30-40 lbs.
Bulldog (American) 18-24" 60-120 lbs.
Bulldog (English) 18-24" 40-55 lbs.
Bulldog (French) 12-16" 18-28 lbs.
Bull Terrier 12- 18" 50-60 lbs.
Cairn Terrier 10-16" 12-16 lbs.
Chihuahua 8-14" 2-6 lbs.
Chinese Crested 8-11" 5-10 lbs.
Chow 18-24" 45-65 lbs.
Cocker Spaniel 12-18" 24-60 lbs.
Collie 18-22" 50-75 lbs.
Corgi 14-16" 25-38 lbs.
Dachshund Standard 16-20" 16-32 lbs.
Dachshund Mini 8-18" 9-15 lbs.
Dalmation 14-20" 45-65 lbs.
Doberman 18-24" 66-88 lbs.
Fox Terrier 10-16" 14-18 lbs.
German Shepherd 18-24" 65-95 lbs.
Golden Retriever 16-24" 55-75 lbs.
Great Dane 20-26" 125-135 lbs.
Great Pyrenees 24-30" 90-125 lbs.
Greyhound 14-18" 55-80 lbs.
Greyhound (Italian) 8-11" 7-12 lbs.
Jack Russell Terrier 10-14" 9-15 lbs.
Lab 18-24" 55-75 lbs.
Lhasa Apso 12-16" 13-15 lbs.
Maltese 10-14" 6-9 lbs.
Papillon 8-12" 9-11 lbs.
Pekingnese 12-16" 8-10 lbs.
Pit Bull 14-18" 30-70 lbs.
Pomeranian 10-14" 9-13 lbs.
Poodle (Mini) 10-16" 24-28 lbs.
Poodle (Standard) 12-18" 45-70 lbs.
Poodle (Toy) 8-14" 12-17 lbs.
Pug 12-16" 14-18 lbs.
Rottweiler 24-30" 100-120 lbs.
St. Bernard 26-32" 130-230 lbs.
Schnauzer (Giant) 20-26" 70-80 lbs.
Schnauzer (Standard) 14-20" 30-35 lbs.
Schnauzer (Mini) 10-16" 13-15 lbs.
Scottish Terrier 14-20" 19-23 lbs.
Shar Pei 16-20" 35-55 lbs.
Shih Tzu 10-14" 12-16 lbs.
Springer Spaniel 14-18" 49-55 lbs.
Staffordshire Terrier 14-20" 50-65 lbs.
Weimaraner 16-22" 55-85 lbs.
Wheaten Terrier 18-22" 32-37 lbs.
Yorkshire Terrier 6-12" 6-9 lbs.