Quote Originally Posted by Jay_Bunny View Post
And Purple, if you keep the male in 24/7, you can usually expect a litter from each female every 3 weeks. On occasion, they won't get pregnant right after giving birth and will breed after their litter is weaned and you have to wait an additional 3 weeks for that female. A mouse can have many many babies, but if you go by 10 babies per female, then every 3 weeks, you should get 30-ish babies.
In theory this is true, but in reality, at least in my experience, you won't end up with that many babies. Some times females won't get pregnant on schedule. Some litters will be small, especially at first, until you've had a few generations to selectively breed for better breeders. Some babies just won't thrive. Some litters may get eaten, again especially at first.

I recently read a post from someone that if I remember correctly, they were running 100 female mice, and producing 500 mice/month. That's only 5 babies per female each month. I can probably find the post if you are interested in seeing it.