Does 550g of wet food per day sound about right for a 6.5kg 11yo neutered male cat? He is the right weight for his size.
I used to feed MrCat 3 pouches of wet food a day and as much Meowing Heads dry food as he could be bothered to dig out of the slow feeder. The wet food was a mixture of Felix 100g pouches and Waitrose 85g pouches, so about 285g/day. (Because he had dries ad lib, we weren't too bothered whether he had 1 Waitrose and 2 Felix or the other way around.)
Meowing Heads changed the recipes I think, because MrCat started puking it up. When I took away the dries he stopped puking.
So for the moment he is only having wet food. I'm not sure how much to give him. If I go by Waitrose's recommendation of 1 sachet per kg, he needs about 550g of wet food. Does that sound right?