Carbs in Red Onion
Keto-friendlyRed Onion (per 100 g) contains 9.9g total carbs, 7.7g net carbs, 0.1g fat, 0.9g protein, and 44 calories.
Last updated June 10, 2026 · Reviewed by Jordan Lee, RD, Registered Dietitian
7.7g
Net carbs
9.9g
Total carbs
2.2g
Fiber
0.9g
Protein
0.1g
Fat
44
Calories
Values per 100 g.
Carbs by serving size
| Serving | Net carbs | Total carbs | Protein | Calories |
|---|---|---|---|---|
| 100 g (3.5 oz) | 7.7g | 9.9g | 0.9g | 44 |
| 1 oz (28 g) | 2.2g | 2.8g | 0.3g | 12 |
Nutrition facts
| Nutrient | Amount (per 100 g) |
|---|---|
| Calories | 44 |
| Total carbs | 9.9g |
| Net carbs | 7.7g |
| Fiber | 2.2g |
| Sugar | 0g |
| Sugar alcohols | 0g |
| Protein | 0.9g |
| Fat | 0.1g |
| Sodium | 1mg |
| Potassium | 197mg |
Source: USDA FoodData Central (Foundation). Net carbs = total carbs − fiber − sugar alcohols, computed by CarbMeNot.
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Frequently asked questions
- How many carbs are in red onion?
- Red Onion has 9.9g of total carbs and 7.7g of net carbs per 100 grams.
- How many net carbs are in red onion?
- Red Onion has 7.7g of net carbs per 100 grams (total carbs 9.9g minus 2.2g fiber).
- Is red onion keto-friendly?
- Yes — with 7.7g net carbs per 100g, red onion fits a ketogenic diet in normal portions.
- How many calories are in red onion?
- Red Onion has 44 calories per 100 grams.
