Calories in oats
Rolled oats (dry) contains 379 calories per 100g, with 13.2g of protein, 6.5g of fat and 67.7g of carbohydrates. A serving of 1/2 cup, dry (40g) comes to roughly 152 calories.
Calories by serving size
Based on 379 kcal per 100g (dry).
| 1/2 cup, dry (40g) | 152 kcal |
|---|---|
| 1 cup, dry (81g) | 307 kcal |
| 100g | 379 kcal |
Full nutrition facts
Per 100g, dry.
| Energy | 379 kcal |
|---|---|
| Protein | 13.2 g |
| Total fat | 6.5 g |
| Saturated fat | 1.1 g |
| Carbohydrate | 67.7 g |
| Sugars | 1.0 g |
| Fibre | 10.1 g |
| Sodium | 6 mg |
| Cholesterol | 0 mg |
| Potassium | 362 mg |
How this fits a day of eating
A 40g serving of dry rolled oats, about half a cup, is roughly 152 calories, under 8% of a 2,000 calorie day, before milk or toppings. Oats are calorie-dense when dry but absorb a lot of liquid, so a modest dry portion turns into a large, filling bowl of porridge.
Weigh oats dry, not cooked. The toppings are where breakfast calories climb: a tablespoon of peanut butter adds about 95 calories and a tablespoon of honey about 64.
Common questions
How many calories are in a bowl of oatmeal?
A typical bowl made from 40g of dry rolled oats, about half a cup, contains roughly 152 calories and 5g of protein when cooked with water. Using a cup of whole milk instead adds about 149 calories. Sweeteners, nut butters and dried fruit can easily double the total, so log toppings separately.
Are oats good for weight loss?
Oats are a good choice for many people trying to lose weight. They contain beta-glucan, a soluble fibre that thickens in the gut and helps slow digestion, and 40g of dry oats swells into a large bowl for about 152 calories. The benefit depends on keeping portions and toppings measured.
Why do oats have so many calories per 100g?
The 379 calories per 100g refers to dry oats, which contain very little water. Once cooked, oats absorb several times their weight in liquid, so 100g of porridge made with water is only around 70 calories. Always check whether a nutrition figure refers to dry or cooked oats before logging it.
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Nutrition values from USDA FoodData Central, FDC ID 173904, per 100g unless stated. Last reviewed 18 September 2026. Calorie needs vary by person.