Peanut butter serving size, cups to grams and 30 g of protein
Here a serving of peanut butter is counted as 2 tbsp, which USDA weighs at 1.1 oz (32 g), with 191 calories and 7.1 g protein. One cup weighs 9.1 oz (258 g). For 30 g of protein you need 4.8 oz (135 g), about 1/2 cup, with 808 calories.
Serving sizes of peanut butter
Every household measure USDA weighs for this food, plus 1 oz and 100 g.
| Measure | Weight | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| 1 cup | 9.1 oz (258 g) | 1543 calories | 57.3 g | 57.6 g | 132.5 g |
| 2 tbsp | 1.1 oz (32 g) | 191 calories | 7.1 g | 7.1 g | 16.4 g |
| 1 oz | 1 oz (28 g) | 170 calories | 6.3 g | 6.3 g | 14.6 g |
| 100 g | 3.5 oz (100 g) | 598 calories | 22.2 g | 22.3 g | 51.4 g |
Cups to grams
USDA weighs 1 cup of peanut butter at 258 g. Smaller measures follow from it (1 cup = 16 tbsp = 48 tsp).
| Measure | Weight | Calories |
|---|---|---|
| 1 cup | 9.1 oz (258 g) | 1543 calories |
| 3/4 cup | 6.8 oz (194 g) | 1157 calories |
| 2/3 cup | 6.1 oz (172 g) | 1029 calories |
| 1/2 cup | 4.6 oz (129 g) | 771 calories |
| 1/3 cup | 3 oz (86 g) | 514 calories |
| 1/4 cup | 2.3 oz (64 g) | 386 calories |
| 1 tbsp | 16.1 g | 96 calories |
| 1 tsp | 5.4 g | 32 calories |
Grams and ounces to cups
| Weight | Volume | Calories |
|---|---|---|
| 1 oz | 1.8 tbsp | 170 calories |
| 100 g (3.5 oz) | 1/3 cup | 598 calories |
| 1 lb (454 g) | 1 3/4 cups | 2712 calories |
What 3.5 oz (100 g) of peanut butter looks like
3.5 oz (100 g) of peanut butter is 3.5 oz, or about 1/3 cup. It has 598 calories, 22.2 g protein, 22.3 g carbs and 51.4 g fat.
How much peanut butter for 30 g of protein
There is 22.2 g of protein in 3.5 oz (100 g) of peanut butter. 30 g of protein takes 4.8 oz (135 g), about 1/2 cup, which comes with 808 calories.
| Protein | Weight | About | Calories |
|---|---|---|---|
| 20 g | 3.2 oz (90 g) | 1/3 cup | 538 calories |
| 30 g | 4.8 oz (135 g) | 1/2 cup | 808 calories |
| 40 g | 6.4 oz (180 g) | 2/3 cup | 1077 calories |
| 50 g | 7.9 oz (225 g) | 3/4 cup | 1346 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 2026-10-14)
- Peanut butter (smooth style): Peanut butter, smooth style, without salt, FDC ID 172470 (SR Legacy, published 2019-04-01)
- 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.