Oatmeal serving size, cups to grams
Here a serving of cooked oatmeal is counted as 1 cup (cooked), which USDA weighs at 8.5 oz (240 g), with 154 calories and 5.3 g protein. 100 g (3.5 oz) is about 1/2 cup.
Serving sizes of cooked oatmeal
Every household measure USDA weighs for this food, plus 1 oz and 100 g.
| Measure | Weight | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| 1 cup, cooked | 8.5 oz (240 g) | 154 calories | 5.3 g | 27.3 g | 2.6 g |
| 1 oz | 1 oz (28 g) | 18 calories | 0.63 g | 3.2 g | 0.31 g |
| 100 g | 3.5 oz (100 g) | 64 calories | 2.2 g | 11.4 g | 1.1 g |
Cups to grams
USDA weighs 1 cup (cooked) of cooked oatmeal at 240 g. Smaller cup measures follow from it.
| Measure | Weight | Calories |
|---|---|---|
| 1 cup | 8.5 oz (240 g) | 154 calories |
| 3/4 cup | 6.3 oz (180 g) | 115 calories |
| 2/3 cup | 5.6 oz (160 g) | 102 calories |
| 1/2 cup | 4.2 oz (120 g) | 77 calories |
| 1/3 cup | 2.8 oz (80 g) | 51 calories |
| 1/4 cup | 2.1 oz (60 g) | 38 calories |
Grams and ounces to cups
| Weight | Volume | Calories |
|---|---|---|
| 1 oz | 1/8 cup | 18 calories |
| 100 g (3.5 oz) | 1/2 cup | 64 calories |
| 1 lb (454 g) | 2 cups | 290 calories |
What 3.5 oz (100 g) of oatmeal looks like
3.5 oz (100 g) of cooked oatmeal is 3.5 oz, or about 1/2 cup. It has 64 calories, 2.2 g protein, 11.4 g carbs and 1.1 g fat.
How much oatmeal for 30 g of protein
There is 2.2 g of protein in 3.5 oz (100 g) of cooked oatmeal, so 30 g of protein would take 47.9 oz (1357 g), about 5 2/3 cups, with 869 calories. It is not a practical way to reach a protein target.
Dry to cooked
USDA survey data for cooked oatmeal:
- 1 cup dry makes 17.1 oz (485 g) cooked, about 2 cups
- 1 oz dry makes 6 oz (170 g) cooked, about 3/4 cup
Keep exploring
Sources
Weights and nutrition: USDA FoodData Central, food portions and nutrients (FoodData Central, April 2026 release, accessed 2026-10-13)
- Oatmeal (regular or quick, made with water, no added fat): Oatmeal, regular or quick, made with water, no added fat, FDC ID 2708381 (FoodData Central survey (FNDDS) 2024-10-31)
- Kitchen measures (1 cup = 16 tbsp, 1 tbsp = 3 tsp): NDSU Extension, Ingredient Substitutions (FN198, J. Garden-Robinson, April 2013 edition). https://www.extension.purdue.edu/extmedia/HHS/HHS-784-W.pdf (accessed 2026-10-12)
How we calculate: each household measure is the gram weight USDA lists for this food. Calories and nutrients are the USDA values per 3.5 oz (100 g) scaled to that weight. 1 oz = 28.35 g and 1 lb = 453.6 g. Cup fractions are rounded to the nearest kitchen measure. A dash (—) means USDA reports no value. How we verify.