Onion rings serving size, cups to grams
Here a serving of frozen onion rings is counted as 1 piece, which USDA weighs at 20.2 g, with 58 calories and 0.91 g protein. One cup weighs 1.7 oz (48 g).
Serving sizes of frozen onion rings
Every household measure USDA weighs for this food, plus 1 oz and 100 g.
| Measure | Weight | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| 1 cup | 1.7 oz (48 g) | 138 calories | 2.2 g | 17.4 g | 6.9 g |
| 10 rings, large | 2.5 oz (71 g) | 204 calories | 3.2 g | 25.8 g | 10.2 g |
| 10 rings, medium | 2.1 oz (60 g) | 173 calories | 2.7 g | 21.8 g | 8.6 g |
| 10 rings, small | 1.7 oz (48 g) | 138 calories | 2.2 g | 17.4 g | 6.9 g |
| 1 piece | 20.2 g | 58 calories | 0.91 g | 7.3 g | 2.9 g |
| 1 oz | 1 oz (28 g) | 82 calories | 1.3 g | 10.3 g | 4.1 g |
| 100 g | 3.5 oz (100 g) | 288 calories | 4.5 g | 36.3 g | 14.4 g |
Cups to grams
USDA weighs 1 cup of frozen onion rings at 48 g. Smaller cup measures follow from it.
| Measure | Weight | Calories |
|---|---|---|
| 1 cup | 1.7 oz (48 g) | 138 calories |
| 3/4 cup | 1.3 oz (36 g) | 104 calories |
| 2/3 cup | 1.1 oz (32 g) | 92 calories |
| 1/2 cup | 24 g | 69 calories |
| 1/3 cup | 16 g | 46 calories |
| 1/4 cup | 12 g | 35 calories |
Grams and ounces to cups
| Weight | Volume | Calories |
|---|---|---|
| 1 oz | 2/3 cup | 82 calories |
| 100 g (3.5 oz) | 2 1/8 cups | 288 calories |
| 1 lb (454 g) | 9 1/2 cups | 1306 calories |
What 3.5 oz (100 g) of onion rings looks like
3.5 oz (100 g) of frozen onion rings is 3.5 oz, or about 2 1/8 cups or 5 pieces. It has 288 calories, 4.5 g protein, 36.3 g carbs and 14.4 g fat. One piece weighs 20.2 g.
How much onion rings for 30 g of protein
There is 4.5 g of protein in 3.5 oz (100 g) of frozen onion rings, so 30 g of protein would take 23.4 oz (664 g), about 13 3/4 cups, with 1912 calories. It is not a practical way to reach a protein target.
Keep exploring
Sources
Weights and nutrition: USDA FoodData Central, food portions and nutrients (FoodData Central, April 2026 release, accessed 2026-10-14)
- Frozen onion rings (breaded, par fried): Onion rings, breaded, par fried, frozen, prepared, heated in oven, FDC ID 324317 (Foundation Foods, 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.