Calories in Onions, raw
Generic food Raw Vegetables
This record duplicates Onion, raw from another USDA dataset. Its values are kept for reference; the linked page is the main one.
Onions, raw contains 38 kcal per 100 g. A typical serving of 1 slice (15 g) provides about 6 kcal.
Roughly 89% of its calories come from carbohydrates, with 9% from protein and 2% from fat (estimated with general energy factors).
The data comes from the USDA Food and Nutrient Database for Dietary Studies (FNDDS), which calculates values from recipes of the ingredients.
Nutrition facts
| Nutrient | Amount per 100 g | % DV |
|---|---|---|
| Calories C | 38 kcal | |
| Total fat C | 0.08 g | 0.1% |
| Saturated fat C | 0.042 g | 0.2% |
| Cholesterol C | 0 mg | 0% |
| Sodium C | 1 mg | 0% |
| Total carbohydrates C | 8.5 g | 3% |
| Dietary fiber C | 1.7 g | 6% |
| Total sugars C | 5.8 g | |
| Protein C | 0.86 g | 2% |
| Vitamin A C | 0 µg | 0% |
| Vitamin C C | 8.2 mg | 9% |
| Vitamin D C | 0 µg | 0% |
| Vitamin E C | 0.02 mg | 0.1% |
| Vitamin K C | 0.4 µg | 0.3% |
| Thiamin (B1) C | 0.046 mg | 4% |
| Riboflavin (B2) C | 0.027 mg | 2% |
| Niacin (B3) C | 0.12 mg | 0.7% |
| Vitamin B6 C | 0.12 mg | 7% |
| Folate (B9) C | 19 µg | 5% |
| Vitamin B12 C | 0 µg | 0% |
| Choline C | 6.1 mg | 1% |
| Calcium C | 17 mg | 1% |
| Iron C | 0.24 mg | 1% |
| Magnesium C | 9 mg | 2% |
| Phosphorus C | 33 mg | 3% |
| Potassium C | 171 mg | 4% |
| Zinc C | 0.17 mg | 2% |
| Copper C | 0.041 mg | 5% |
| Selenium C | 0 µg | 0% |
% DV: percent of the FDA Daily Value for adults (reference amounts). Letters show how each value was obtained: M measured, C calculated, L label, Z assumed zero, I imputed. Vitamins and minerals not listed were not reported by the source.
Nutritional breakdown
- Protein 9%
- Carbohydrates 89%
- Fat 2%
Approximate share of calories, using general energy factors (4 kcal/g protein and carbohydrate, 9 kcal/g fat, 7 kcal/g alcohol).
Vitamins and minerals, % Daily Value per 100 g
Nutritional insights
- Protein per 100 kcal2.3 gprotein density, useful for comparing foods with different calorie levels
- Water90.3 gwater per 100 g, which largely explains differences between raw, cooked and dried forms
Full nutrient profile
Fats and cholesterol (2)
| Monounsaturated fat C | 0.013 g |
|---|---|
| Polyunsaturated fat C | 0.017 g |
Individual fatty acids (19)
| EPA (omega-3, 20:5 n-3) C | 0 g |
|---|---|
| DHA (omega-3, 22:6 n-3) C | 0 g |
| Linoleic acid (omega-6, 18:2) C | 0.013 g |
| SFA 4:0 C | 0 g |
| SFA 6:0 C | 0 g |
| SFA 8:0 C | 0 g |
| SFA 10:0 C | 0 g |
| SFA 12:0 C | 0 g |
| SFA 14:0 C | 0.004 g |
| SFA 16:0 C | 0.034 g |
| SFA 18:0 C | 0.004 g |
| MUFA 18:1 C | 0.013 g |
| PUFA 18:3 C | 0.004 g |
| PUFA 20:4 C | 0 g |
| MUFA 16:1 C | 0 g |
| PUFA 18:4 C | 0 g |
| MUFA 20:1 C | 0 g |
| MUFA 22:1 C | 0 g |
| PUFA 22:5 n-3 (DPA) C | 0 g |
Carotenoids (6)
| Beta-carotene C | 1 µg |
|---|---|
| Lycopene C | 0 µg |
| Lutein + zeaxanthin C | 4 µg |
| Retinol C | 0 µg |
| Carotene, alpha C | 0 µg |
| Cryptoxanthin, beta C | 0 µg |
Other components (8)
| Water C | 90.3 g |
|---|---|
| Alcohol C | 0 g |
| Caffeine C | 0 mg |
| Theobromine C | 0 mg |
| Folic acid C | 0 µg |
| Folate, food C | 19 µg |
| Vitamin E, added C | 0 mg |
| Vitamin B-12, added C | 0 µg |
Frequently asked questions
How many calories are in raw onions?
100 g of raw onions has 38 kcal. 1 slice (15 g): about 6 kcal. 1 ring (5 g): about 2 kcal. 1 whole (148 g): about 56 kcal.
How much protein is in raw onions?
Raw onions contains 0.86 g of protein per 100 g (2% of the 50 g Daily Value), or 0.13 g in 1 slice (15 g). About 9% of its calories come from protein.
How many carbs are in raw onions?
Raw onions has 8.5 g of total carbohydrates per 100 g, including 1.7 g of fiber and 5.8 g of sugars.
How much fat is in raw onions?
Raw onions contains 0.08 g of fat per 100 g, of which 0.042 g is saturated (0.2% of the Daily Value).
How much sodium is in raw onions?
100 g contains 1 mg of sodium, 0% of the 2,300 mg Daily Value.
Where does this nutrition data come from?
From USDA FoodData Central: FNDDS (Survey), record dated October 31, 2024. FoodFactly last checked it on November 6, 2026. Each value above shows whether it was measured, calculated or taken from a label.
Source of the nutrition information
- USDA FoodData Central: FNDDS (Survey), record 2709795. License: CC0 1.0 (U.S. public domain). Source record dated October 31, 2024. Imported November 6, 2026.
Last updated: . Data quality score: 100/100 (how it is calculated).
General nutrition information, not medical advice. Individual needs differ; see our disclaimer.