I just weighed the boys, it's so easy on the digital bathroom scales with a handful of dreamies. (A big favourite here) Luther is now 3 kg and Perry is 3.5 kg. Perry was 3.4 kg the last time I weighed him months ago, but was only 2.5 kg when he was neutered at 6 and a half months. He's 16 months now so I would imagine he's at his optimum size. I still think Luther will be a much bigger cat, but hopefully not 6.7kg like my beautiful fat friend!