In that case, I would say that 4 pinkies or 2 decent size fuzzy mice 2-3 times a week would do him fine for now. Of course the size of the meal will need to grow as the animal does. As far as I know, there is no "calculated" rate of feeding set. However, if you might consider emailing Adam Britton at abritton@crocodlian.com and he might be able to answer that for you. I am sure that there are a few others in here that might happen to have that answer for you, but I personally dont. I kinda feed my alligator in the same way sorta that I feed my snakes. Depending on how much I feed, will determine the size and quantity of the previous meal.
Example, If I feed my burmese a Jumbo rat that leaves a nice size lump in her, I dont feed again for another couple of weeks, until that I see she has slendered back out. However if I feed her just a large rat, that is a bit smaller, I will feed her one of those every week to every two weeks.
Younger crocodilians will feed more frequently. In my opinion, feeding them more times a week, but smaller portions is much better than throwing them a giant meal at one time. That is just my opinion, that I go by from what I have read and learned from my own personal experiences with my gator.
Hope this helps,
Stan