Calories in oatmeal (cooked with water)
Calories, protein, carbohydrate and fat per 100 g and per serving, from the USDA reference database — plus what actually changes the number on your plate.
Short answer
100 g of oatmeal (cooked with water) contains 71 kcal, with 2.5 g of protein, 12 g of carbohydrate and 1.5 g of fat.
A typical serving — 1 cup, about 234 g — is roughly 166 kcal.
That makes it a low-calorie food: you can eat a large portion for very little.
Nutrition facts
| Nutrient | Per 100 g | 1 cup (234 g) |
|---|---|---|
| Calories | 71 kcal | 166 kcal |
| Protein | 2.5 g | 5.9 g |
| Carbohydrates | 12 g | 28.1 g |
| Sugars | 0.3 g | 0.6 g |
| Fibre | 1.7 g | 4 g |
| Fat | 1.5 g | 3.6 g |
| Saturated fat | 0.3 g | 0.7 g |
| Cholesterol | 0 mg | 0 mg |
| Sodium | 4 mg | 9 mg |
| Potassium | 70 mg | 164 mg |
| Calcium | 9 mg | 21 mg |
| Iron | 0.9 mg | 2.1 mg |
| Vitamin C | 0 mg | 0 mg |
| Water | 84 g | 196 g |
Calories per serving
| Serving | Weight | Calories | Protein | Carbohydrates | Fat |
|---|---|---|---|---|---|
| 1 cup | 234 g | 166 | 5.9 g | 28.1 g | 3.6 g |
| 1 bowl | 250 g | 178 | 6.4 g | 30 g | 3.8 g |
Photograph it instead of looking it up
Wellix identifies oatmeal on your plate, estimates the portion and logs calories, protein, carbs and fat in seconds. Free to start on iPhone and Android.
Calories by weight
Use this table when you know the weight but not the serving:
| Amount | Calories | Protein | Carbohydrates | Fat |
|---|---|---|---|---|
| 25 g | 18 | 0.6 g | 3 g | 0.4 g |
| 50 g | 36 | 1.3 g | 6 g | 0.8 g |
| 100 g | 71 | 2.5 g | 12 g | 1.5 g |
| 150 g | 107 | 3.8 g | 18 g | 2.3 g |
| 200 g | 142 | 5.1 g | 24 g | 3 g |
| 250 g | 178 | 6.4 g | 30 g | 3.8 g |
| 300 g | 213 | 7.6 g | 36 g | 4.6 g |
Where the calories come from
Calories come from three macronutrients: protein and carbohydrate at 4 kcal per gram, fat at 9 kcal per gram. For oatmeal (cooked with water) the split is:
- Protein: 2.5 g × 4 = 10 kcal — 14% of calories
- Carbohydrates: 12 g × 4 = 48 kcal — 67% of calories
- Fat: 1.5 g × 9 = 14 kcal — 19% of calories
- Most of the energy in oatmeal (cooked with water) comes from carbohydrate (67% of calories).
- For 200 kcal you can eat about 280 g.
Compare preparations
The same food, prepared differently. Cooking removes water (so calories per 100 g rise), adds fat (so they rise further), or both.
| Preparation | Calories | Protein | Carbohydrates | Fat |
|---|---|---|---|---|
| Oatmeal (cooked with water)this page | 71 | 2.5 g | 12 g | 1.5 g |
| Oats (dry, uncooked) | 379 | 13.2 g | 67.7 g | 6.5 g |
What actually changes the number
Porridge cooked with water is 71 kcal per 100 g — a bowl is 150–180 kcal. Made with whole milk it is nearer 250, and each tablespoon of honey, sugar or nut butter adds 60–100.
How accurate are these numbers?
The values on this page are reference averages from the USDA FoodData Central database (SR Legacy release), measured on samples of oatmeal as sold and prepared in the United States. Your portion will differ: produce varies by variety and ripeness, meat by cut and trim, and anything cooked by the fat and water it gained or lost.
For most foods the per-100 g figure is reliable to within about 10%. The larger uncertainty is almost always the weight of what is on your plate and the cooking fat you cannot see — the two things worth checking before you worry about the database.
How accurate are AI calorie counting apps? →
Related foods
More in Grains, rice, pasta and bread →
Frequently asked questions
How many calories are in 100 g of oatmeal?
100 g of oatmeal (cooked with water) contains 71 kcal (2.5 g protein, 12 g carbohydrate, 1.5 g fat), according to USDA reference data.
How many calories are in a serving of oatmeal?
A typical serving of oatmeal — 1 cup, about 234 g — has roughly 166 kcal. Weigh your own portion once to see how it compares; serving sizes vary more than the food does.
How much protein is in oatmeal?
Oatmeal (cooked with water): 2.5 g of protein per 100 g, which is low. Foods above about 15–20 g per 100 g, or where protein supplies a third or more of the calories, are usually considered high-protein.
What amount of oatmeal equals 200 kcal?
At 71 kcal per 100 g, about 280 g of oatmeal equals 200 kcal.
Can I track oatmeal by taking a photo?
Yes. A photo calorie app like Wellix identifies oatmeal on the plate and estimates the portion from the image. The estimate is most accurate when you confirm the weight or the count, and tell the app about anything the camera cannot see — cooking oil, butter, dressings and sauces.
Source
Nutrition data: U.S. Department of Agriculture, FoodData Central — SR Legacy, FDC ID 173905: "Cereals, oats, regular and quick, unenriched, cooked with water (includes boiling and microwaving), without salt". Values are per 100 g of edible portion. Serving weights are USDA household measures or typical retail sizes; check the label where one exists. View the USDA record.
Wellix provides general nutrition information and is not medical advice. Nutrition values are reference averages and individual foods vary. Consult a qualified healthcare professional before making significant dietary changes.
Photograph it instead of looking it up
Wellix identifies oatmeal on your plate, estimates the portion and logs calories, protein, carbs and fat in seconds. Free to start on iPhone and Android.
