Onion: Carbs, Protein, Fat & Calories
One serving of onion (1 medium (110 g)) has 10.2 g carbs (8.4 g net), 1.2 g protein, 0.1 g fat and 44 calories. Change the amount below to calculate any portion.
* Based on a 2,000-calorie diet. Rounded averages from USDA FoodData Central.
Onion by serving size
| Serving | Calories | Carbs | Net carbs | Protein | Fat |
|---|---|---|---|---|---|
| 1 medium (110 g) | 44 | 10.2 g | 8.4 g | 1.2 g | 0.1 g |
| 1 oz (28 g) | 11 | 2.6 g | 2.2 g | 0.3 g | 0 g |
| 100 g | 40 | 9.3 g | 7.6 g | 1.1 g | 0.1 g |
Key facts
- 88% of its calories come from carbs, 10% from protein and 2% from fat — it is mainly a carbohydrate food.
- Among the 8 foods in Vegetables, it ranks #7 of 8 for lowest net carbs per 100 g.
- One serving (1 medium, 110 g) is 0.7 carb choices (15 g each) — useful for diabetes carb counting.
Compare with other vegetables (per 100 g)
| Food | Calories | Carbs | Net carbs | Protein | Fat |
|---|---|---|---|---|---|
| Broccoli (Cooked) | 35 | 7.2 g | 3.9 g | 2.4 g | 0.4 g |
| Spinach (Raw) | 23 | 3.6 g | 1.4 g | 2.9 g | 0.4 g |
| Carrot (Raw) | 41 | 9.6 g | 6.8 g | 0.9 g | 0.2 g |
| Tomato | 18 | 3.9 g | 2.7 g | 0.9 g | 0.2 g |
| Onion | 40 | 9.3 g | 7.6 g | 1.1 g | 0.1 g |
| Green Peas (Cooked) | 84 | 15.6 g | 10.1 g | 5.4 g | 0.2 g |
| Cauliflower (Raw) | 25 | 5 g | 3 g | 1.9 g | 0.3 g |
| Romaine Lettuce | 17 | 3.3 g | 1.2 g | 1.2 g | 0.3 g |
Frequently asked questions
How many carbs are in onion?
One serving of onion (1 medium, 110 g) has 10.2 g of carbohydrate, including 1.9 g of fiber, so 8.4 g net carbs. Per 100 g it has 9.3 g carbs (7.6 g net).
How much protein is in onion?
One serving of onion (1 medium, 110 g) has 1.2 g of protein (2% of the daily value). Per 100 g it has 1.1 g of protein.
How much fat and how many calories are in onion?
One serving of onion (1 medium, 110 g) has 44 calories and 0.1 g of fat, of which 0 g is saturated. Per 100 g: 40 calories and 0.1 g fat.
Is onion keto-friendly?
In small amounts. One serving of onion (1 medium, 110 g) has 8.4 g net carbs — 42% of a strict 20 g/day keto limit.
Calculators
- Carb Counter — add onion to a meal and track carbs and net carbs.
- Protein Calculator — how much protein you need per day.
- Fat Calculator — your daily fat and saturated fat limits.