How many calories are in an onion?
1 medium onion (110 g) of onion has 44 calories — with 1.2 g of protein, 10.3 g of carbs, and 0.1 g of fat, according to USDA nutrition data.
Onion nutrition facts
| Nutrient | Per 1 medium onion | Per 100 g |
|---|---|---|
| Calories | 44 | 40 |
| Protein | 1.2 g | 1.1 g |
| Carbohydrates | 10.3 g | 9.34 g |
| of which fiber | 1.9 g | 1.7 g |
| of which sugars | 4.7 g | 4.24 g |
| Fat | 0.1 g | 0.1 g |
| of which saturated | 0 g | 0.04 g |
| Sodium | 4 mg | 4 mg |
| Potassium | 161 mg | 146 mg |
Source: USDA FoodData Central, SR Legacy — Onions, raw
Where the calories come from
Of the 44 calories in 1 medium onion of onion, roughly 41 come from carbohydrates, 5 from protein, and 1 from fat.
Frequently asked questions
How many calories are in an onion?
1 medium onion (110 g) of onion has about 44 calories, based on USDA data (40 calories per 100 g).
How much protein is in an onion?
1 medium onion (110 g) provides about 1.2 g of protein (1.1 g per 100 g).
How many carbs are in an onion?
1 medium onion (110 g) has about 10.3 g of carbohydrates, including 1.9 g of fiber.
Is onion good for weight loss?
At 44 calories per 1 medium onion, onion fits easily into a calorie deficit — the key is what it's paired with and total daily calories.
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