Foods · Vegetables
Calories in onion
Onion: about 40 calories per 100 g. A portion of 1 cup, chopped (160 g) has about 64 calories.
Calories and nutrients by portion
| Portion | Grams | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|---|
| 100 g (3.5 oz) | 100 g | 40 | 1.1 g | 9.3 g | 0.1 g |
| 1 cup, chopped | 160 g | 64 | 1.8 g | 14.9 g | 0.2 g |
| 1 cup, sliced | 115 g | 46 | 1.3 g | 10.7 g | 0.1 g |
| 1 tbsp chopped | 10 g | 4 | 0.1 g | 0.9 g | 0 g |
| 1 large | 150 g | 60 | 1.7 g | 14 g | 0.2 g |
| 1 slice, large (1/4" thick) | 38 g | 15 | 0.4 g | 3.5 g | 0 g |
Where the calories come from
- Protein 10%
- Carbs 88%
- Fat 2%
Shares are estimated with 4 calories per gram of protein and carbohydrate and 9 per gram of fat.
Full nutrition per 100 g
| Calories | 40 kcal |
| Protein | 1.1 g |
| Carbohydrate | 9.3 g |
| of which sugars | 4.2 g |
| Fibre | 1.7 g |
| Fat | 0.1 g |
| of which saturated | 0 g |
| Cholesterol | 0 mg |
| Sodium | 4 mg |
| Potassium | 146 mg |
| Calcium | 23 mg |
| Iron | 0.2 mg |
| Vitamin C | 7.4 mg |
| Water | 89.1 g |
How it compares with other vegetables
Among the 28 vegetables listed on this site, onion ranks number 19 from the lowest in calories per 100 g, and number 19 from the highest in protein per 100 g.
Fewer calories per 100 g
- Kale 35 cal
- Pumpkin (canned) 34 cal
- Broccoli 34 cal
More calories per 100 g
- Carrots 41 cal
- Beets 43 cal
- Brussels sprouts 43 cal
What 64 calories equal in exercise
For a 155 lb (70 kg) person, Harvard Health lists about 133 calories for 30 minutes of walking at 3.5 mph and about 288 for 30 minutes of running at 5 mph. By that chart, a portion of onion (1 cup, chopped, 64 calories) equals about 14 minutes of walking or 7 minutes of running. Use the calories burned calculator for your own weight.
About these numbers
The figures come from the USDA FoodData Central entry “Onions, raw”. They describe the raw food. Cooking changes the water content, so calories per 100 g will differ once it is cooked. They are reference averages, so brands, ripeness, cuts and recipes shift the real number. Treat them as estimates, and weigh food for the closest result.
Quick answers
How many calories are in onion (1 cup, chopped)?
About 64 calories (≈). That is 1 cup, chopped (160 g) of onion, using the USDA reference value of 40 calories per 100 g.
How many calories are in 100 grams of onion?
About 40 calories (≈). One ounce (28 g) is about 11 calories.
How much protein is in onion?
1.1 g per 100 g, and about 10% of its calories come from protein (≈). A portion of 1 cup, chopped has about 1.8 g.
Source
- USDA FoodData Central, SR Legacy: Onions, raw (FDC ID 170000)
- U.S. Department of Agriculture, Agricultural Research Service. FoodData Central. fdc.nal.usda.gov
- Harvard Health: calories burned in 30 minutes for people of three different weights
General information, not medical advice. Nutrient values are estimates and vary by product and portion.
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