Well there's not really a age-to-weight standard it could depend on a lot of different factors like genetics, prey size, health, sex. I have a female around 8 mos old weighs around 700 grams and a 7 mo that weighs a little over 350 g. Generally speaking I would say at 12 months about 750 grams. I always figure about they gain about 100 g a month in my experience. How much does yours weigh curently? What are you feeding? How long have you had it?