How many calories are in 100 g of rolled oats?

December 18, 2025 •

3 min read

According to the USDA, a 100-gram serving of raw rolled oats contains approximately 379 calories. This wholesome grain is also a powerhouse of essential nutrients, including significant amounts of fiber, protein, and various vitamins and minerals. The final calorie count of your oatmeal, however, can change based on what you add to it.

Quick Summary

A 100 g portion of raw rolled oats provides around 379 calories, along with substantial amounts of protein, fiber, and micronutrients like manganese and phosphorus. The total energy value is influenced by cooking method and added ingredients.

Key Points

Calories per 100g: 100 grams of dry, raw rolled oats contains approximately 379 calories.
Nutrient Density: Rolled oats are a rich source of carbohydrates, protein, fiber, and essential minerals like manganese and phosphorus.
Cooking doesn't add calories: Cooking oats in water does not increase the calorie count; the calorie change occurs with added ingredients.
Supports Weight Management: The high fiber content promotes fullness, which can help with appetite control and weight loss.
Heart Health Benefits: Soluble fiber (beta-glucan) in oats can help lower cholesterol and regulate blood sugar.
Versatile Ingredient: Rolled oats are suitable for both quick-cooking porridge and for use in baking and overnight oat recipes.

Detailed Nutritional Profile of 100g Rolled Oats

Beyond just the calorie count, 100 grams of raw rolled oats offers a comprehensive nutritional profile that contributes to a healthy diet. This serving size delivers significant levels of carbohydrates, protein, and dietary fiber, as well as essential micronutrients. A typical breakdown includes approximately 13 grams of protein, 68 grams of carbohydrates, and 10 grams of dietary fiber. This nutrient density is what makes oatmeal a filling and nutritious meal that can support weight management and overall health.

Macronutrient and Micronutrient Breakdown

In addition to the main macronutrients, rolled oats are packed with important vitamins and minerals. The fiber content, especially the soluble fiber known as beta-glucan, is particularly notable for its health benefits, which include lowering cholesterol levels and helping to regulate blood sugar.

Carbohydrates: The primary component by weight, providing a steady release of energy throughout the day.
Protein: A higher protein content than many other grains, supporting muscle maintenance and repair.
Fiber: Rich in both soluble and insoluble fiber, which benefits digestive health and promotes feelings of fullness.
Manganese: An excellent source of this mineral, which is vital for bone health, growth, and metabolism.
Phosphorus: Important for bone health and tissue maintenance.
Iron: A crucial component of hemoglobin, which transports oxygen in the blood.
Magnesium: Involved in numerous bodily processes, and often lacking in modern diets.

Raw vs. Cooked: How Calories are Affected

It is important to understand that cooking rolled oats in water does not add any calories; it simply increases the volume by absorbing the water. If you cook 100 grams of dry rolled oats, the calorie content will remain the same. The total calories of your breakfast will only increase if you add calorie-dense ingredients like milk, honey, sugar, fruits, or nuts.

For example, a half-cup of dry oats (approximately 40g) cooked in one cup of water with a tablespoon of milk and a teaspoon of honey will be significantly lower in calories than a full cup (80g) cooked with whole milk, maple syrup, and multiple toppings. This distinction is key for those tracking calorie intake for weight loss.

Comparison Table: Rolled Oats vs. Steel-Cut Oats

While rolled oats and steel-cut oats come from the same whole oat groat, their processing, cooking time, and some nutritional attributes differ slightly. This table highlights the key differences to help you choose the best type for your needs.


Feature	Rolled Oats (Old-Fashioned)	Steel-Cut Oats (Irish Oats)
Processing	Steamed and flattened into flakes	Chopped into pieces with steel blades
Cooking Time	Shorter, typically 5-10 minutes	Longer, often 15-30 minutes
Texture	Creamier and softer when cooked	Chewier and nuttier
Glycemic Index (GI)	Slightly higher GI, faster digestion	Lower GI, slower digestion
Nutritional Profile	Very similar in macronutrient and fiber content per dry weight	Very similar in macronutrient and fiber content per dry weight
Versatility	Excellent for baking, granola, and overnight oats	Best for hearty porridge and slow-cooker meals

Health Benefits of Incorporating Rolled Oats into Your Diet

Including rolled oats in your regular diet offers a multitude of health benefits, thanks to their rich fiber and nutrient content. Beyond their calorie count, their ability to promote satiety and support heart health makes them an excellent choice for a balanced lifestyle.

List of benefits:

Supports Heart Health: The soluble fiber, beta-glucan, helps lower LDL (bad) cholesterol, which reduces the risk of heart disease.
Aids in Weight Management: The high fiber content keeps you feeling full longer, which helps curb appetite and reduces overall calorie intake throughout the day.
Regulates Blood Sugar: Beta-glucan helps to slow down the absorption of glucose, preventing sharp spikes and crashes in blood sugar levels.
Promotes Digestive Health: Both soluble and insoluble fiber help maintain bowel regularity and promote a healthy gut microbiome.
Packed with Antioxidants: Oats contain unique antioxidants called avenanthramides, which have anti-inflammatory properties and may help regulate blood pressure.

Conclusion

In summary, 100 grams of raw rolled oats contains approximately 379 calories, providing a nutrient-dense foundation for a healthy meal. The exact caloric value of your final dish will depend heavily on your preparation method and added ingredients. While they share a similar nutritional profile with steel-cut oats, rolled oats offer a faster cooking time and softer texture, making them a versatile choice for various meals. By focusing on smart preparation and mindful toppings, you can enjoy all the health benefits of rolled oats while effectively managing your calorie intake.

Frequently Asked Questions

No, cooking rolled oats in water does not change the calorie count of the original dry portion. The calorie content only increases when other ingredients like milk, sweeteners, or toppings are added.

On a per-serving dry weight basis, the nutritional values of rolled and steel-cut oats are very similar. The main differences are in their cooking time, texture, and glycemic index, with steel-cut oats having a slightly lower GI due to less processing.

To reduce calories, prepare your oatmeal with water instead of milk, use a natural low-calorie sweetener like stevia, and choose low-sugar toppings such as fresh berries or a sprinkle of cinnamon instead of dried fruits or excessive honey.

Yes, rolled oats can be an excellent food for weight loss due to their high fiber content, which helps you feel full for longer and controls appetite. This can prevent overeating and help you manage your calorie intake effectively.

Instant oats are more heavily processed than rolled oats, meaning they are cut into smaller pieces and pre-cooked to allow for faster preparation. They often have a higher glycemic index and can contain added sugars, making rolled or steel-cut oats generally better for weight management.

Pure oats are naturally gluten-free. However, they are often processed in facilities that also handle wheat, barley, and rye, which can lead to cross-contamination. People with celiac disease or gluten sensitivity should look for oats specifically certified as gluten-free.

A 100-gram serving of dry rolled oats typically contains around 10 to 11 grams of dietary fiber. This includes a significant amount of soluble fiber called beta-glucan, which has numerous health benefits.