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Onion Calories and nutrition facts · Vegetables

32 kcal per medium (110 g)
Carbs
5.3 g
Fibre
1.9 g
Sugars
5.3 g
Protein
1.4 g
Fat
0.11 g
29 kcal per 100 g
Carbs
4.8 g
Fibre
1.7 g
Sugars
4.8 g
Protein
1.3 g
Fat
0.1 g

Where the calories come from

Protein 20% Carbs 76% Fat 4%

Onion has 32 kcal per medium (110 g), with 5.3 g carbs, 1.9 g fibre, 1.4 g protein and 0.11 g fat. 100 g has 29 kcal.

Share of your daily needs in one medium

Diet tags

Cholesterol reduced Egg free Gluten free Lacto-ovo vegetarian Lactose free Lacto vegetarian Low protein Milk free Low gluten No added salt Soy free Unsweetened Vegan

Last updated November 2, 2026 · Where the data comes from

Get to know onion in Nutriely

These numbers are one piece of the puzzle. Nutriely shows what it adds to your whole day, how much of it fits before a limit like saturated fat or sodium, and which foods fill the gaps it leaves.

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Other forms of onion

How it compares with other vegetables

Per 100 g, against the 99 vegetables in our catalog.

  • Calories 29 kcal · typical 32 kcal
  • Vitamin K 0.7 µg · typical 30.5 µg

    Less vitamin K than 90% of vegetables.

  • Vitamin C 10.2 mg · typical 21 mg
  • Folate 13.5 µg · typical 51 µg

    Less folate than 88% of vegetables.

  • Vitamin A 0.57 µg · typical 50 µg

    Less vitamin A than 89% of vegetables.

  • Potassium 220 mg · typical 350 mg

    Less potassium than 87% of vegetables.

The bar shows this food; the line marks the typical (median) value of the category.

Learn about onion

What are the health benefits of onions?

Onions are a good source of vitamin C, fiber, and antioxidants, which may help boost immunity, improve heart health, and reduce inflammation. They also contain compounds that have anti-cancer and antibacterial properties.

What are the health risks associated with onions?

Onions are generally safe for consumption, but they may cause digestive discomfort in some individuals, especially when consumed in large quantities. People with onion allergies may experience symptoms such as oral allergy syndrome, hives, or digestive issues. Additionally, some individuals may experience heartburn or acid reflux after consuming onions. It's important to moderate onion consumption and monitor any adverse reactions.

Can someone be allergic to onions?

Yes, an onion allergy is possible. It may cause symptoms such as itching, hives, swelling, or difficulty breathing in some individuals. If you suspect an onion allergy, it is important to consult with a healthcare professional for proper evaluation and diagnosis.

Nutrients in onion

Pick an amount to see what it gives you. Tap a nutrient to learn what it does.

% of the daily value for a healthy adult. Your own needs depend on age, sex and activity.

Energy and macros
Vitamins
Minerals
Carbohydrates
Fats
Amino acids

Amino acid data is mapped from the USDA database, for information only.

Onion in other food databases

The same food in national food composition databases, next to ours. Per 100 g.

Per 100 g Nutriely BLS Fineli USDA
Energy (kcal) 29 34 29 40
Protein (g) 1.25 1.16 1.25 1.1
Fat (g) 0.1 0.15 0.1 0.1
Carbohydrates (g) 4.8 6.01 4.8 7.64
Sugars (g) 4.8 6.01 4.8 4.24
Fibre (g) 1.7 1.4 1.7 1.7

Compare every nutrient across databases

Switch between Nutriely, BLS, Fineli and USDA for all the vitamins, minerals and amino acids of onion in the Nutriely app.

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BLS: “Onion raw” · Fineli: “Onion” · USDA: “Onions, raw”. Databases measure different samples, so some spread is normal. Nutriely's values are what the app uses. Sources and licences.

Similar vegetables

Closest in calories first.

Where the data comes from

How we combine and check nutrition data: Nutriely data sources.

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