Given weights in short descriptions of a parrot species are just observed ranges. There are wide ranges of weights and size within any given species, just as there are with human beings. So don't fret much about the total weight of your parrot. In example, Salty's species, yellow shoulder Amazon, those websites say the range is 280-320gr. But Salty weighs in at 340 and has for many years. He is also bigger in stature then other YSA we have met.
However, do monitor his weight regularly, say 3 or4 times a week, or more. Keep a journal of the results. WHY? Parrots will ALWAYS try to hide outward signs of illness, which is normal for any prey animal, and parrots are prey. Thats because in the wild, the ill or sick parrots are the first to be predated upon. The one thing parrots cannot hide is losing weight when sick or ill. A drop of more then, oh, 2-5% over a few days is cause for concern and a vet visit is in order.
Also, you can determine how much of that weight is fat and how much is muscle. Holding the bird firmly but gently, feel around on his chest for his keel bone. If it is sticking out or is very prominent when you feel for it, the bird is underweight. If it feels like it is firm, not only directly on the keel bone but in the adjacent areas, that is flight muscle. If it feels sort squishy, its likely fats.