Water serving size, cups to grams
Here a serving of water is counted as 1 cup, which USDA weighs at 8.4 oz (237 g), with 0 calories and 0 g protein. 100 g (3.5 oz) is about 1/2 cup.
Serving sizes of water
Every household measure USDA weighs for this food, plus 1 oz and 100 g.
| Measure | Weight | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| 1 cup | 8.4 oz (237 g) | 0 calories | 0 g | 0 g | 0 g |
| 1 ml | 1 g | 0 calories | 0 g | 0 g | 0 g |
| 1 fl oz | 1 oz (30 g) | 0 calories | 0 g | 0 g | 0 g |
| 1 oz | 1 oz (28 g) | 0 calories | 0 g | 0 g | 0 g |
| 100 g | 3.5 oz (100 g) | 0 calories | 0 g | 0 g | 0 g |
Cups to grams
USDA weighs 1 cup of water at 237 g. Smaller measures follow from it (1 cup = 16 tbsp = 48 tsp).
| Measure | Weight | Calories |
|---|---|---|
| 1 cup | 8.4 oz (237 g) | 0 calories |
| 3/4 cup | 6.3 oz (178 g) | 0 calories |
| 2/3 cup | 5.6 oz (158 g) | 0 calories |
| 1/2 cup | 4.2 oz (118 g) | 0 calories |
| 1/3 cup | 2.8 oz (79 g) | 0 calories |
| 1/4 cup | 2.1 oz (59 g) | 0 calories |
| 1 tbsp | 14.8 g | 0 calories |
| 1 tsp | 4.9 g | 0 calories |
Grams and ounces to cups
| Weight | Volume | Calories |
|---|---|---|
| 1 oz | 1.9 tbsp | 0 calories |
| 100 g (3.5 oz) | 1/2 cup | 0 calories |
| 1 lb (454 g) | 2 cups | 0 calories |
What 3.5 oz (100 g) of water looks like
3.5 oz (100 g) of water is 3.5 oz, or about 1/2 cup. It has 0 calories, 0 g protein, 0 g carbs and 0 g fat. One ml weighs 1 g.
Keep exploring
Sources
Weights and nutrition: USDA FoodData Central, food portions and nutrients (FoodData Central, April 2026 release, accessed 2026-10-13)
- Water (bottled, generic): Water, bottled, generic, FDC ID 174158 (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.