How much do rats weigh?

Males are between 350-450 grams full grown. The alpha in the cage will generally grow bigger than the others.  They can also get “bigger” if you overfeed them, but that will lead to health issues.

Females are between 250-350 grams full grown.  Females are less likely to overeat than males.  Females that have raised litters tend to grow larger with each pregnancy due to the hormones.