One US gallon of milk weighs 8.6 pounds, but there is much more to the conversion details.
Before that, some interesting facts about milk:
Milk is the first food any mammal experiences, but only humans learned to exploit other animals’ milk as a rich food source that does not involve killing animals.
Around 8,000 years ago, early humans in northern cold climates learned the value of fermented milk products and then evolved to remain capable of digesting milk for their entire adult lives.
Weight and Volume
The weight and volume of any material have a direct relationship.
If you know the weight of a material, you can calculate the volume it can occupy, and if you know the volume, you can calculate the weight.
This relationship between weight and volume makes it easy to cook a recipe using a set of measuring cups – the recipe translates the ingredients’ weight into easy to remember quantities of cups and spoons (volumes).
It is much easier for many people to measure and visualize a cup than the equivalent weight of the ingredient.
Metric and Imperial Measurements
The metric set of measurements (liters, grams, kilograms, centimeters, and meters) give precise scientific measures that mean the same worldwide.
Most scientists use metric values for clarity – the same as using Latin names for plants and animals.
Imperial measurements (gallons, pounds, ounces, and inches) were a more local measurement system.
Pounds, ounces, and inches are the same across the globe, but gallons differ between US and UK measurements.
This difference is not surprising when you consider that two towns in the same country would have different time before fast travel between places. Local measurements of time and liquid were local solutions to trade and business.
Now we are all familiar with time zones, but we have a standardized clock that gives the “true” time. Or rather, the time that humans designate as the time.
How Much Does a Gallon of Milk Weigh?
If you want to know how much a gallon of milk weighs in pounds and ounces, you need to clarify if you are talking US or UK measurements.
Although a UK ounce is identical to a US ounce and both systems have sixteen ounces in a pound, the gallon’s volume is different. You are talking about a consistent measurement of weight in grams and kilograms, but you are still comparing different volumes.
If you want to be scientifically accurate in answering the question: how much does a gallon of milk weigh?
You need to define the percentage of fat in the milk. The measurements below refer to the “normal” full-fat milk.
One US gallon of full-fat milk weighs 8.6 lbs, 137.6 oz, or 3.9kg.
More details are in the table:
|Amount of Milk
|1 gallon US
|1 gallon UK or CA
|1 liter of milk
How Much Does a Gallon of Milk Weigh in Pounds?
One US gallon of milk weighs 8.6 pounds, while one UK or CA gallon of milk weighs 10.3 pounds.
How Much Does a Gallon of Milk Weigh in Ounces?
A gallon of milk weighs 137.6 ounces in the US measurements, while a gallon of that same milk in the UK or CA measurements weighs 164.8 ounces.
How Much Does a Gallon of Milk Weigh in Kilograms and Grams?
A US gallon of milk is 3.9 kilograms (3,900 grams), and a UK gallon of milk is 4.67 kilograms (4,670 grams).
Weight of a Gallon of Milk in US Measurements (Table)
Milk in US gallon converted into pounds, ounces, kilograms, and grams:
Weight of a Gallon of Milk in UK/Canadian Measurements (Table)
Milk in UK/CA gallon (also known as the Imperial gallon) converted into pounds, ounces, kilograms, and grams:
Is Milk Heavier than Water?
Milk is about 87% water (the balance is solids like fat and minerals), but the addition of 13% other material means milk is a little bit heavier than water.
How much does a gallon of milk weigh compared to a gallon of water?
If we are talking about US gallons – milk weighs 8.6 lbs, and water weighs 8.33 lbs, or about 3% heavier than water.
Now, the exact weight of milk depends on the amount of milk fat in the gallon of milk. You find milk with different colored bottle tops describing different fat levels – and these vary between the US and the UK.
In the US, milk is:
- Whole milk containing 3.5% fat.
- Reduced-fat milk containing 2% fat.
- Low-fat milk containing 1% fat.
- Skim milk (fat-free milk or non-fat milk) containing 0% fat.
In the UK, milk is:
- Whole milk containing 3.5-4% fat.
- Semi-skimmed containing approximately 1.8% fat.
- Skimmed milk can contain up to 0.1% fat.
- Breakfast or Channel Island milk from Jersey cows containing 5-5.5% fat.
When you remove the fat, you approach the weight of water, but milk is a denser liquid than water and will always weigh slightly more.
What About Frozen Milk?
When you think: how much does a gallon of milk weigh frozen?
You are probably thinking about what happens when you put a gallon of milk in the freezer.
One gallon of milk always contains one gallon of milk – if you take one gallon of milk and freeze it, you are still dealing with the same amount of milk.
Milk contains 87% water, and water does something extraordinary when it freezes. Unlike every other liquid on the planet, water expands when it approaches the freezing point.
That unique property can result in your plastic milk bottle splitting down the seam in the freezer because as the ice expands, it puts pressure on the container – ice occupies 9% more space than water.
If you freeze a gallon of milk, you get the same weight as the gallon of liquid milk.
But if you compare a gallon of frozen milk with a gallon of liquid milk, the gallon of frozen milk weighs less because it contains less liquid milk.
When you are thinking about frozen milk, you are thinking about the nature of water.
Sometimes in the freezing, you get separation of milk solids from the water content. When you defrost your milk, you need to shake well to recombine.
What About Other Kinds of Milk?
When we talk about milk, it is usually milk from a dairy cow, but milk can refer to milk alternatives and milk from other animals like sheep, goats, buffalo, reindeer, yak, or camel.
Different animal milks produce different levels of fats – sheep’s milk contains about twice the fat content of cow’s milk.
The higher fat content contributes to a richer, creamier taste and makes ewe’s milk a prime ingredient for luxurious cheeses and yogurts.
The higher fat content means that a gallon of sheep’s milk will weigh a bit more than a gallon of cow’s milk because it has a higher density.
Nut milk or other dairy alternatives involve pulverizing a solid material in water to produce a milky liquid suspension.
The weight of these kinds of milk depends on the proportion of material in the recipe. But it will differ from the weight of a gallon of cow’s milk and a gallon of water.
How Much Does a Gallon of Milk Weigh Without the Water?
A gallon of milk is 87% water, and water is the bulk of the weight.
If you evaporate the water, you can get condensed milk with less water or create a dried powder.
Milk powder means you can transport vast gallons of milk and store it for longer than the fresh product.
A gallon of US milk yields approximately 1lb of milk powder. That means you can carry between eight and ten times the amount of milk as a dried powder, which is an essential consideration in transport costs.
Milk powder is a useful ingredient in many food products and forms the basis for baby milk formula as an alternative to breast milk.
How much does a gallon of milk weigh?
It depends on where you live, the type of milk, and the water content.