Tub size for 3 rats?

I want to start breeding rats because I've had too many times where I bought rats that were the wrong size, plus I just inherited another snake who's going to be on rats soon and it's getting pretty expensive.

I want to start with 2 females and one male, but I don't know how much space 3 rats need.

Also, I have a cage that is 2x1x1, would that be big enough to house a pregnant mom and her babies until they are 4 weeks old? The cage is made from 1/4" wire.

I'm using jumbo size cat litter pans for my rats. It sounds like your cage should be big enough for a pregnant female.