Every dog is different! Just as humans don't all eat the same amount, neither do dogs.
What we look at instead is age and activity level, and then make adjustments if any need to be made.
Generally you should start by giving your dog a percentage of their ideal body weight.
Adult dogs age 4+ yrs = 1.5% of body weight
Younger, active adult dogs, age 1.5 to 4 yrs = 2.0% of body weight
Teen Dogs, 1 to 1.5 yrs old = 2.5% of body weight
Puppies up to 1 yr old= 3.0+% of body weight
Dog's Ideal Weight x % according to age, activity level = Total food weight per day 50 lbs x 0.02 = 1.0 lbs per day
If after a couple of weeks your dog has gained or lost more weight than you would like on the raw food then you can increase or decrease the food a tablespoon at a time until they maintain the weight you would like. Also, no one says that you have to feed your dog the exact same amount every day! You can give your dog more food on an active day and less food on a lazy day.