Perfect size for my 35 lb beagle mix. The airline requires a few inches of head space for the animal to turn around and be comfortable. He is in between this size and the next one down, so I went bigger to be on the safe side. I am glad I did. I have a 1 inch pad in there at the moment, but plan to have a 3 inch one when we fly. The recommended size for him would have been too small.