Red onion: calories and nutrition facts
Red onion has 35 kcal per 100 g. One serving, 1 Onion (150 g), has 53 kcal.
- Calories
- 35 kcal
- Protein
- 1.3 g
- Carbohydrates
- 5.6 g
- Fat
- 0.4 g
Per 100 g
Red onion: how many calories?
Red onion has 35 kcal per 100 g, with 1.3 g protein, 5.6 g carbs and 0.4 g fat. A 150 g serving (1 Onion) has 53 kcal. That is less than the average for Fruits & Veggies (109 kcal per 100 g). Most of its calories come from carbohydrates.
Where the calories come from
- Protein17%
- Carbohydrates72%
- Fat11%
Calculate a portion
- Calories
- 53 kcal
- Protein
- 2 g
- Carbohydrates
- 8.4 g
- Fat
- 0.6 g
Nutrition facts
| Nutrient | Per 100 g | Per serving (150 g) |
|---|---|---|
| Calories | 35 kcal | 53 kcal |
| Fat | 0.4 g | 0.6 g |
| of which saturated fat | 0.1 g | 0.2 g |
| Carbohydrates | 5.6 g | 8.4 g |
| of which sugars | 5.2 g | 7.8 g |
| Fiber | 2.5 g | 3.8 g |
| Protein | 1.3 g | 2 g |
| Sodium | 5 mg | 8 mg |
| Water | 90.3 g | 135.5 g |
| Vitamin C | 4.1 mg | 6.1 mg |
| Calcium | 22 mg | 33 mg |
| Iron | 0.2 mg | 0.3 mg |
| Potassium | 190 mg | 285 mg |
| Magnesium | 9 mg | 14 mg |
Source: Ciqual food composition table (ANSES, France). Data updated on 2 September 2026.
Share of reference intakes
Per 100 g, compared with an adult's reference intakes (2,000 kcal a day, Regulation (EU) No 1169/2011).
| Nutrient | Of reference intake |
|---|---|
| Calories(35 kcal) | 2% |
| Fat(0.4 g) | 1% |
| of which saturated fat(0.1 g) | 1% |
| Carbohydrates(5.6 g) | 2% |
| of which sugars(5.2 g) | 6% |
| Protein(1.3 g) | 3% |
| Salt(0.01 g) | 0% |
What the EU thresholds say
Nutrition claim thresholds from Regulation (EC) No 1924/2006, per 100 g.
- Low energy (40 kcal or less)
- Source of protein (at least 12% of calories)
- Low fat (3 g or less)
- Low sodium (120 mg or less)
Red onion: frequently asked questions
Red onion: how many calories per serving?
A 150 g serving (1 Onion) has 53 kcal.
Red onion: how much protein?
Red onion contains 1.3 g of protein per 100 g, 3% of the 50 g reference intake.
Red onion: how much fibre?
Red onion provides 2.5 g of fibre per 100 g, 10% of the 25 g a day recommended by EFSA.
Red onion: how much makes 100 kcal?
100 kcal is about 286 g of this food.
Recipes with this food
More foods in this category
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- Red bell pepper34 kcal
- Red berries0 kcal
- Red cabbage26 kcal
- Red chicory19 kcal
- Red kuri squash22 kcal
- Red radish11 kcal
- Redcurrant67 kcal
- Reduced sugar apple compote64 kcal
- Reduced sugar fruit compote64 kcal
- Rhubarb18 kcal
- Rhubarb compote111 kcal
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