Carbs in White Onion
Keto-friendlyHow many carbs are in white onion?
White Onion has 6.5g net carbs per 100g — 7.7g total carbs minus 1.2g fiber — plus 0.9g protein, 0.1g fat, and 35 calories. That makes white onion relatively low in net carbs and lower than the typical vegetable, which averages about 17.9g net carbs per 100g. With this carb count, white onion fits a keto or low-carb diet (usually 20–50g net carbs per day) in normal portions. Values are per per 100 g, sourced from USDA FoodData Central; net carbs are computed by CarbMeNot.
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Last updated June 10, 2026 · Reviewed by Jordan Lee, Nutrition Editor
Values per 100 g.
Is white onion keto-friendly?
Yes, white onion can fit a keto diet in moderate portions. It has 6.5g net carbs per 100g (7.7g total carbs − 1.2g fiber). On a standard keto diet (20–50g net carbs per day), that leaves plenty of room for other vegetables and meals.
Carbs by serving size
| Serving | Net carbs | Total carbs | Protein | Calories |
|---|---|---|---|---|
| 100 g (3.5 oz) | 6.5g | 7.7g | 0.9g | 35 |
| 1 oz (28 g) | 1.8g | 2.2g | 0.3g | 10 |
How many calories are in white onion?
White Onion has 35 calories per 100g. That's alongside 0.9g protein, 0.1g fat, and 6.5g net carbs per 100g.
Nutrition facts
| Nutrient | Amount (per 100 g) |
|---|---|
| Calories | 35 |
| Total carbs | 7.7g |
| Net carbs | 6.5g |
| Fiber | 1.2g |
| Sugar | 0g |
| Sugar alcohols | 0g |
| Protein | 0.9g |
| Fat | 0.1g |
| Sodium | 2mg |
| Potassium | 141mg |
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 white onion?
- White Onion has 7.7g of total carbs and 6.5g of net carbs per 100 grams.
- How many net carbs are in white onion?
- White Onion has 6.5g of net carbs per 100 grams (total carbs 7.7g minus 1.2g fiber).
- Is white onion keto-friendly?
- Yes, white onion can fit a keto diet in moderate portions. It has 6.5g net carbs per 100g (7.7g total carbs − 1.2g fiber). On a standard keto diet (20–50g net carbs per day), that leaves plenty of room for other vegetables and meals.
- How many calories are in white onion?
- White Onion has 35 calories per 100 grams.
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CarbMeNot provides general nutrition information, not medical advice. Values are estimates — verify before relying on them for any health decision. See our Medical Disclaimer.