A gallon of milk weighs around 8.6 lbs or 3.90 kg
This is a common question that arises when someone goes to buy a milk bag. When buying a gallon of milk, we usually think about how much it weighs, and if it is light enough, can a gallon bottle be taken home?
One gallon of water contains 3.79 liters. 3.79 liters is 3.79 kilograms in terms of water. So 3.79 kilograms of water is equal to 8.35552 pounds. But in case of milk we need to consider density of milk, which is higher than water.
The comparison between the weights of gallon milk and water at average temperature and pressure is important. Since the density of milk is greater than the density of water, its weight will be greater than the weight of water at the same conditions.
So 1 US gallon of milk = 3.7854*1.03 = 3.9 Kg
If you convert Kg to pounds, 3.90 kg x 2.2 =8.6 pounds.
So a gallon of milk weighs 8.6 pounds or 3.90 kg.