Oats serving size, cups to grams and 30 g of protein
Here a serving of raw oats is counted as 1 cup, which USDA weighs at 2.8 oz (80 g), with 303 calories and 10.5 g protein. 100 g (3.5 oz) is about 1 1/4 cups. For 30 g of protein you need 8 oz (228 g), about 2 3/4 cups, with 865 calories.
Serving sizes of raw oats
Every household measure USDA weighs for this food, plus 1 oz and 100 g.
| Measure | Weight | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| 1 cup | 2.8 oz (80 g) | 303 calories | 10.5 g | 54.2 g | 5.2 g |
| 1 oz | 1 oz (28 g) | 107 calories | 3.7 g | 19.2 g | 1.8 g |
| 100 g | 3.5 oz (100 g) | 379 calories | 13.2 g | 67.7 g | 6.5 g |
Cups to grams
USDA weighs 1 cup of raw oats at 80 g. Smaller measures follow from it (1 cup = 16 tbsp = 48 tsp).
| Measure | Weight | Calories |
|---|---|---|
| 1 cup | 2.8 oz (80 g) | 303 calories |
| 3/4 cup | 2.1 oz (60 g) | 227 calories |
| 2/3 cup | 1.9 oz (53 g) | 202 calories |
| 1/2 cup | 1.4 oz (40 g) | 152 calories |
| 1/3 cup | 0.9 oz (27 g) | 101 calories |
| 1/4 cup | 20 g | 76 calories |
| 1 tbsp | 5 g | 19 calories |
| 1 tsp | 1.7 g | 6 calories |
Grams and ounces to cups
| Weight | Volume | Calories |
|---|---|---|
| 1 oz | 1/3 cup | 107 calories |
| 100 g (3.5 oz) | 1 1/4 cups | 379 calories |
| 1 lb (454 g) | 5 2/3 cups | 1719 calories |
What 3.5 oz (100 g) of oats looks like
3.5 oz (100 g) of raw oats is 3.5 oz, or about 1 1/4 cups. It has 379 calories, 13.2 g protein, 67.7 g carbs and 6.5 g fat.
How much oats for 30 g of protein
There is 13.2 g of protein in 3.5 oz (100 g) of raw oats. 30 g of protein takes 8 oz (228 g), about 2 3/4 cups, which comes with 865 calories.
| Protein | Weight | About | Calories |
|---|---|---|---|
| 20 g | 5.4 oz (152 g) | 2 cups | 576 calories |
| 30 g | 8 oz (228 g) | 2 3/4 cups | 865 calories |
| 40 g | 10.7 oz (304 g) | 3 3/4 cups | 1153 calories |
| 50 g | 13.4 oz (380 g) | 4 3/4 cups | 1441 calories |
Weights are for the form named above.
Keep exploring
Sources
Weights and nutrition: USDA FoodData Central, food portions and nutrients (FoodData Central, April 2026 release, accessed 2026-10-13)
- Raw oats: Oats, raw, FDC ID 2708489 (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.