TempoLife › Calorie database › Vegetables › Red onion
Red onion calories and nutrition facts
100 grams of red onion contains 40 calories, with 1.1 g of protein, 9.3 g of carbohydrate and 0.1 g of fat. It provides 1.7 g of fiber per 100 g. Most of its calories come from carbohydrate.
Where the calories come from
Protein 10% Carbs 88% Fat 2%
How red onion compares
Per 100 g, against the closest vegetables in this database.
| Food | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| Red onion | 40 kcal | 1.1 g | 9.3 g | 0.1 g |
| Onion | 40 kcal | 1.1 g | 9.3 g | 0.1 g |
| Carrot juice, canned | 40 kcal | 1 g | 9.3 g | 0.2 g |
| Carrot | 41 kcal | 0.9 g | 9.6 g | 0.2 g |
| Frozen butternut squash, cooked | 39 kcal | 1.2 g | 10.1 g | 0.1 g |
Nutrition facts for red onion
| Nutrient | Per 100 g |
|---|---|
| Calories | 40 kcal |
| Protein | 1.1 g |
| Carbohydrate | 9.3 g |
| Fat | 0.1 g |
| Fiber | 1.7 g |
Print an EU-style nutrition label for red onion — per 100 g and per portion.
Calories in common red onion servings
How many calories in a portion of red onion — reference serving estimates with the gram weight shown.
| Serving | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| 100 g (100 g) | 40 kcal | 1 g | 9 g | 0 g |
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Frequently asked questions
How many calories are in red onion?
Red onion has 40 calories per 100 grams.
How much protein is in red onion?
Red onion contains 1.1 g of protein per 100 g.
Are these red onion calories exact?
No. These are per-100-gram reference values from the older curated row with unverified provenance. Portion size, ripeness, cut and cooking method all change the real number, so treat them as an estimate and log your own portion.
Related foods
Source status: curated_unverified. The original provenance and value-reuse rights were not retained, so no license is asserted for this row's nutrition values. Unknown sugar is shown as unavailable, not measured zero. Reference values per 100 g edible portion.
