How many carbs and sugars are in a glass of milk?

November 26, 2025 •

2 min read

According to the USDA, a standard 8-ounce glass of whole cow's milk contains approximately 12 grams of carbohydrates, all of which are from naturally occurring sugars. This means that when you consider how many carbs and sugars are in a glass of milk, the numbers are essentially the same for plain, unflavored varieties. The total amount can vary slightly depending on the fat content and whether it's plain or flavored.

Quick Summary

An 8-ounce glass of plain cow's milk typically contains around 12 grams of carbohydrates and 12 grams of natural sugar, known as lactose. This content is consistent across whole, 2%, and skim milk, while flavored milks contain added sugar.

Key Points

Consistent Content: A standard 8-ounce glass of plain cow's milk, regardless of fat percentage (whole, 2%, skim), contains approximately 12 grams of carbohydrates and 12 grams of natural sugar (lactose).
Natural vs. Added Sugars: The sugar in plain milk is natural lactose, while flavored milks contain significant amounts of added sugars that substantially increase the total sugar content.
Impact of Lactose Intolerance: For those with lactose intolerance, the body lacks sufficient lactase enzyme to break down the natural milk sugar, which causes digestive issues.
Ultra-Filtered Alternatives: Some specially processed milks, like ultra-filtered, have reduced lactose and higher protein content, providing a lower-sugar dairy option.
Lactose-Free Solutions: Lactose-free milk has added lactase to pre-digest the lactose, making it easy to consume for most people with lactose intolerance without losing the nutritional benefits of regular milk.
The Whole Nutrient Picture: The natural sugar in milk is delivered alongside 13 other essential nutrients, making the full package beneficial for health, rather than just focusing on the sugar alone.

Understanding Carbohydrates and Sugars in Milk

Milk contains carbohydrates primarily in the form of lactose, a naturally occurring sugar. An 8-ounce serving of plain cow's milk, regardless of fat content (whole, 2%, or fat-free), contains about 12 grams of sugar and carbohydrates. Flavored milks, however, include added sugars on top of the natural lactose.

The Role of Lactose

Lactose is a natural disaccharide in milk. In individuals with sufficient lactase, the enzyme breaks down lactose into glucose and galactose for energy. Lactose intolerance occurs when there is insufficient lactase, leading to digestive discomfort from undigested lactose in the colon.

Milk and Added Sugars: A Crucial Distinction

Reading nutrition labels is essential because flavored milks contain significant added sugars in addition to natural lactose. For example, flavored milk can have roughly double the total sugar of plain milk.

The Impact of Processing: Ultra-Filtered Milk

Ultra-filtered milk undergoes processing to remove some water and lactose, resulting in higher protein and lower sugar content compared to regular milk. An 8-ounce serving might contain only 6 grams of sugar and more protein.

Comparing Different Types of Milk

The table below shows the carbohydrate and sugar content of various milk types per 8-ounce serving:


Milk Type (8 oz)	Total Carbohydrates	Sugars (Lactose)
Whole Milk (3.25%)	~12 grams	~12 grams
Reduced-Fat Milk (2%)	~12 grams	~12 grams
Low-Fat Milk (1%)	~12 grams	~12 grams
Skim Milk	~12 grams	~12 grams
Flavored Milk (e.g., Chocolate)	~24+ grams	~12 grams (natural) + added sugars
Ultra-Filtered Milk	~6 grams	~6 grams
Lactose-Free Milk	~12 grams	~12 grams (but pre-digested)

Lactose-Free and Non-Dairy Options

Lactose-free milk is regular milk with added lactase enzyme to break down lactose, making it digestible for individuals with lactose intolerance while retaining nutrients like calcium and vitamin D. Non-dairy alternatives have different nutritional profiles; check labels for varying carbohydrate and sugar levels, including added sugars.

Conclusion: Making an Informed Choice

Understanding the natural carbs and sugars (lactose) in plain milk, the added sugars in flavored varieties, and the reduced sugar in options like ultra-filtered milk allows for informed dietary choices. Lactose provides natural energy and is part of milk's overall nutritional value, which includes essential vitamins and minerals. For those with lactose intolerance, lactose-free or non-dairy options offer ways to enjoy similar beverages without discomfort. Always review nutritional information to select the best milk type for your health needs.

Outbound Link

For more in-depth information about lactose intolerance and dietary management, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) offers valuable resources: NIDDK - Lactose Intolerance Fact Sheet.

Frequently Asked Questions

No, an 8-ounce glass of whole milk, 2% milk, and skim milk all contain the same amount of carbohydrates and natural sugar, about 12 grams. The difference in these milk types is their fat content.

The sugar naturally found in plain milk is called lactose. In your digestive system, lactose is broken down into glucose and galactose for energy.

Flavored milks, such as chocolate milk, contain the same natural lactose as plain milk but also have added sugars. This can double the total sugar content in a single serving compared to plain milk.

The naturally occurring sugar (lactose) in milk provides energy and is part of a nutrient-dense food package that includes protein, calcium, and vitamin D. For most people without lactose intolerance, the benefits of milk outweigh any concerns about its natural sugar content.

You can check the Nutrition Facts label on the milk carton. It will list both 'Total Sugars' (including natural lactose) and 'Added Sugars'. Plain milk will show 0 grams of added sugars.

Lactose-free milk has the enzyme lactase added during processing to break down the lactose into simpler, more digestible sugars. This makes it easier for people with lactose intolerance to consume dairy without discomfort.

Ultra-filtered milk undergoes a special process to remove some water and lactose, resulting in a product with less sugar and more protein than regular milk. An 8-ounce serving typically has about half the sugar and more protein.