42 is Gurchenko’s waist range (according to the first calculator), not the diameter. And the cat's waist range is 55 cm, by topicstarter, which is surprising. I don’t like Gurchenko, remember 90-60-90. 55 is almost 60. Where have you seen such cats that they have a belly like a typical model? This is not even a meinkun, it is a gepard!
You forget that the typical model is the narrowest place, and the typical cat is the widest!