Milk Weight Calculator – How Much Does Milk Weigh?

Curious how much milk weighs? Enter the volume below to find out!


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How Much Does a Gallon of Milk Weigh?

Did you know that a gallon of milk weighs more than a gallon of water? It seems like an optical illusion since they’re both sold in identically sized jugs, but a gallon of milk actually weighs 8.6 pounds (3.9 kilograms), while a gallon of water weighs a mere 8.3 pounds (or 8.345 pounds to be precise).

That’s based on the density of milk being 1.026 g/cm³ – 1.034 g/cm³.[1]

What’s this milky mystery all about?

Well, it’s all about that fat content in milk. Even though milk is mostly water (about 87.7%), the fat, protein, carbs, and minerals in it make it weigh more than water.

The same goes for half gallons as well. A half-gallon of milk weighs about 4.3 pounds (or 1.95 kilograms). That’s half the volume, and, you guessed it, half the weight of a full gallon.

One gallon of water, on the other hand, weighs 8.345 pounds. So, one gallon of milk actually weighs more than one gallon of water.

Milk weighs more than water because of its higher fat content. Although milk contains 87.7% water, the remainder is fat, protein, carbohydrate, and minerals, which weigh more than water.

As you might imagine, a half-gallon of milk weighs 4.3 pounds or 1.95 kilograms. That’s half the volume and, thus, half the weight of a full gallon.

Steps to Calculate the Weight of a Gallon of Milk

Here’s an easy way to calculate the weight of a gallon of milk:

First, convert the volume of one gallon to cubic centimeters. Since one gallon is equal to 3,785.41 cubic centimeters, you can use the following formula to convert it.

cubic cm = gallons × 3785.41

Simply multiply the volume in cubic centimeters by the density of milk. For example, we know that milk has a density of 1.026 g/cm³ – 1.034 g/cm³, so we’ll use an average of 1.03 g/cm³ in the following formula to get the weight in grams.

weight (grams) = cubic cm × 1.03

Now we know that one gallon of milk weighs 3898.9723 grams. We know that one pound is equal to 453.59237 grams, this next calculation converts that weight result into pounds.

weight (pounds) = weight (grams) ÷ 453.59237

By following the proper steps, you’ll find that one gallon of milk weighs 8.629 pounds (basically 8.6).

Milk Weight Chart

The chart below will help you calculate the weight of milk in cups, pints, quarts, gallons, and liters.

Weight of milk for various volumes
Volume Weight
One Cup 0.5375 lbs (0.2438 kg)
One Pint 1.075 lbs (0.4876 kg)
One Quart 2.15 lbs (0.9752 kg)
One Gallon 8.6 lbs (3.901 kg)
One Liter 2.272 lbs (1.031 kg)

Our gallons to pounds converter will help you calculate the weight of other liquids like honey, oil, and even gasoline in both US and UK gallons.


  1. Anton Paar Ltd, Density measurement of milk and dairy products, The Engineer,