What Smokeycat said.
Figure 10% of the puppies weight and start with that. Watch the waist-line and adjust as needed to keep the puppy growing LEAN.
...really... that's it.
If you start feeding a teenager (6mo-1yr old) on raw, go with the lesser of 10% of current weight or 2.5% of expected adult weight... then adjust as needed to keep the dog LEAN.
If you've been feeding the dog for 4 months... you should already know how much he needs to eat. The %-values are just starting guidelines, NOT fixed targets. It will depend on what kind of food you're feeding THAT DAY (i.e. fatty pork versus lean venison), the activity levels of the dog, the activity levels of THAT DAY, growth rates (which vary day to day), overall temperament (anxious dogs go through more calories) and genetics....
Denna is raw fed, and she gets about 1.5% of her adult weight. She's a low-energy dog with an efficient digestive system!
And really small poops!