Nutrition facts · Vegetables
Calories in Onion
Raw onion has 40 calories per 100 g, and 1 medium onion (110 g) has 44 calories. Almost all of those calories come from carbohydrates, with 9.3 g of carbs per 100 g, including 4.2 g of sugar and 1.7 g of fiber. Protein and fat are very low.
Calories come from: Carbs 88% · Fat 2% · Protein 10%
Common servings
| Serving | Weight | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| Per 100 g | 100 g | 40 kcal | 1.1 g | 9.3 g | 0.1 g |
| 1 medium onion | 110 g | 44 kcal | 1.2 g | 10.3 g | 0.1 g |
| 1 cup, chopped | 160 g | 64 kcal | 1.8 g | 14.9 g | 0.2 g |
| 1 medium slice | 14 g | 6 kcal | 0.2 g | 1.3 g | 0 g |
| 1 tbsp, chopped | 10 g | 4 kcal | 0.1 g | 0.9 g | 0 g |
Full nutrition (Per 100 g)
| Calories | 40 kcal |
|---|---|
| Protein | 1.1 g |
| Carbohydrates | 9.3 g |
| of which sugars | 4.2 g |
| Fiber | 1.7 g |
| Fat | 0.1 g |
| of which saturated | 0 g |
| Sodium | 4 mg |
What changes the calories
- Cooking onions in oil or butter adds the calories of the fat they absorb, which can easily outweigh the onion itself.
- Caramelizing or sautéing drives off water, so a cooked portion weighs less than the raw onion it came from and is more calorie-dense per gram.
- Portion size varies a lot, from a tablespoon sprinkled on a salad to a whole onion in a stir-fry.
- Breaded and fried preparations such as onion rings add calories from both the coating and the frying oil.
Tips for logging it accurately
- Weigh onions raw after peeling and log the raw weight, since that matches the raw nutrition values.
- Log cooking oil or butter as a separate item so the added fat is counted.
- In BerryFit, snap a photo of your meal and adjust the onion portion if it was a large part of the dish.
Log Onion in seconds
Snap a photo of your meal or search for Onion in BerryFit to track calories and macros against your own daily target.
Frequently asked questions
How many calories are in one medium onion?
One medium raw onion (110 g) has 44 calories, with 10.3 g of carbs, 1.2 g of protein and 0.1 g of fat.
How many calories are in a cup of chopped onion?
One cup of chopped raw onion (160 g) has 64 calories and 14.9 g of carbs.
Are onions high in carbs?
Onions are mostly carbohydrate, with 9.3 g of carbs per 100 g, of which 1.7 g is fiber and 4.2 g is sugar. Because onions are usually eaten in small amounts, a typical portion adds only a few grams, such as 0.9 g in a chopped tablespoon.
Do cooked onions have more calories than raw?
The onion itself doesn't gain calories when cooked, but it loses water, so cooked onion has more calories per gram. Any oil or butter used in cooking adds further calories.
Similar foods
Calories in common foodsValues per 100 g from USDA FoodData Central (Onions, raw, FDC ID 170000); servings use USDA portion weights. Real foods vary by variety, ripeness and preparation.
The text on this page was written with the help of AI (Anthropic's Claude) and checked against the numbers in a separate review. The numbers themselves come only from USDA.
