I ordered the critter cap in size large for our dog, Ollie. He is a Great Dane. He has the coat which fits him well and he loves wearing it. He is 2 years old and weighs about 150 pounds, with at least 30 of that being his head! The quality of the hat is great, but unfortunately the hat does not fit properly no matter how I adjust it. I’m thinking if they made it in extra large, it might work. Love Stormy Kromer!