Figuring out quantity help

So My snakes have a weekly consumption of 8 medium rats 4 weaned rats and 2 rat pups. I currently have 7 female rats that are having liters. I'm trying to figure out if I have enough breed able females to keep up with demand. Also about how long does it take a rat to go from birth to a medium sized rat? Trying to figure out how many per month I need to keep for grow out. Just trying to figure everything out any and all information is appreciated.

I think medium size takes six to eight weeks? I'm not 100% on that but I was told to get large rats I need to let them grow for about five months. Like I say I could be wrong and my helpful nature is making me speak to fast lol hopfuly an experienced rat breeder will chime in.

The most commonly used ratio that I see used successfully is a 1:1 ratio of female rat to snake. As for growth rate, you would have your rat pups as soon as the mother gives birth but personally I would wait at least 2-3 days before feeding them off to be sure they get some nutruition in their system from their mother. For a rat to get to weaned size it will be roughly 4-5 weeks from birth. At this early stage they don't really vary in size that greatly so all your rats should roughly be in the same ballpark when it comes to size at this point. Obviously if there is a runt in the litter then this one would be slightly underdeveloped compared to the others and may take more time in the long run to grow out to a fuller size. As for medium size rats, it will vary from rat to rat. From birth it takes roughly 9 months for a rat to reach its full adult size. That being said you would most likely start seeing medium size rats roughly between 8-16 weeks from birth. I hope this help.

I just wanted to clear up an error in my previous post. When I said you would have your rat pups as soon as the mother gave birth, I actuall meant to say pinkies. With that said, you can expect rat pups at 2-3 weeks from birth. Thanks.

You need one female rat for every snake you have than the rest it's all about proper rotation of each females knowing that gestation is 21 days and babies can be weaned at three weeks (time at which a female can get back in breeding rotation)

Pups count 2 weeks
Weaned count 3 weeks
Small count 4 weeks
Medium count 5 to 6 weeks.

Ok so with 7 snakes and 7 female rats what type of rotation should I do so I will have 8 med rats 4 smalls and 2 rat pups per week?