How much does a gallon of milk weigh?

Answer: A gallon of milk weighs 8.6 lbs or 3.90 kg and a quart of milk weighs 2.15 lbs or 0.975kg.

The weight of a gallon of milk can vary depending on the type of milk, as whole milk, 2%, 1%, and skim milk have different fat content. Generally, a gallon of whole milk weighs approximately 8.6 pounds (3.9 kilograms), while a gallon of skim milk weighs around 8.3 pounds (3.8 kilograms). The weight of 2% and 1% milk falls between these two values. Details are given below:

• Whole milk: The densest and heaviest type of milk, weighing in at about 8.6 pounds per gallon.
• 2% milk: Slightly lighter than whole milk, at around 8.5 pounds per gallon.
• 1% milk: Even lighter than 2% milk, weighing about 8.4 pounds per gallon.
• Skim milk: The lightest type of milk, at around 8.3 pounds per gallon.

The weight is derived from the fact that a gallon is a unit of volume, and for liquids like milk, this volume is equivalent to 128 fluid ounces in the United States. As milk has a density of roughly 8.6 pounds per gallon, the weight is calculated by multiplying the volume (128 fluid ounces) by the density.

In conclusion, milk weighs around 8.6 pounds and these values are approximate, actual weights can slightly vary based on factors such as temperature and regional differences in milk composition. Additionally, milk packaging, whether in plastic, glass, or paper containers, contributes to the total weight when purchasing a gallon.