How Much does 1 Gallon of Milk Weigh?

How much a gallon of milk weighs would depend on what type of milk you are buying from the store, whether it is skim, fat-free, 2%, 1%, or whole milk. On average a gallon would weigh about 4 1/2 pounds but of course if the milk came straight from a cow it would weigh allot more because of the fat content.