Vegetable

Onions (raw) Nutrition Facts

USDA description: Onions, raw

Per 100 g, Onions (raw) provides 40 calories. A typical portion, 1 medium (110 g), has 44 calories, 1.2 g protein, 10 g carbs and 0.1 g fat.

calories: 40
protein: 1.1 g
carbs: 9.3 g
fat: 0.1 g

Per 100 g.

Calories and macros per serving

Serving weights are USDA's own for this record; each value is the per-100 g amount scaled to that weight. % = share of the FDA Daily Value.

Onions (raw): calories, protein, carbs, fat, fiber and sugars per serving
Serving	Calories	Protein	Carbs	Fat	Fiber	Sugars
100 g	402%	1.1 g2%	9.3 g3%	0.1 g<1%	1.7 g6%	4.2 g
1 cup, chopped160 g	643%	1.8 g4%	15 g5%	0.2 g<1%	2.7 g10%	6.8 g
1 cup, sliced115 g	462%	1.3 g3%	11 g4%	0.1 g<1%	2 g7%	4.9 g
1 tbsp chopped10 g	4<1%	0.1 g<1%	0.9 g<1%	0 g<1%	0.2 g1%	0.4 g
1 large150 g	603%	1.7 g3%	14 g5%	0.2 g<1%	2.6 g9%	6.4 g
1 slice, large1/4" thick · 38 g	151%	0.4 g1%	3.5 g1%	0 g<1%	0.6 g2%	1.6 g
1 medium2-1/2" dia · 110 g	442%	1.2 g2%	10 g4%	0.1 g<1%	1.9 g7%	4.7 g
1 slice, medium1/8" thick · 14 g	6<1%	0.2 g<1%	1.3 g<1%	0 g<1%	0.2 g1%	0.6 g
1 small70 g	281%	0.8 g2%	6.5 g2%	0.1 g<1%	1.2 g4%	3 g

Calories in kcal. n/r = not reported for this food.

Raw, cooked and other forms

Cooking changes water content, so values per 100 g shift. Each row is its own USDA record.

Form (per 100 g)	Calories	Protein	Carbs	Fat
Onions (raw) (this page)	40	1.1 g	9.3 g	0.1 g
Onions (cooked, boiled, drained, with salt)	42	1.4 g	9.6 g	0.2 g
Onions (cooked, boiled, drained, without salt)	44	1.4 g	10 g	0.2 g

How Onions ranks among vegetables

Rank 1 = the most of that nutrient among the vegetables on CalorieExplorer. Per 200 kcal shows nutrient density: how much you get for the same calories.

Nutrient	Per 100 g	Per 200 kcal
Protein	1.1 g#90 of 123 vegetables	5.5 g#94 of 123 vegetables
Fiber	1.7 g#71 of 112 vegetables	8.5 g#79 of 112 vegetables
Potassium	146 mg#111 of 123 vegetables	730 mg#98 of 123 vegetables
Calcium	23 mg#69 of 123 vegetables	115 mg#74 of 123 vegetables
Iron	0.21 mg#122 of 123 vegetables	1.1 mg#117 of 123 vegetables
Magnesium	10 mg#108 of 122 vegetables	50 mg#111 of 122 vegetables
Vitamin C	7.4 mg#87 of 120 vegetables	37 mg#81 of 120 vegetables

Macronutrient Breakdown

10%

Protein

88%

Carbs

Fat

Compared with the median of vegetables

Per 100 g; median of the 122 vegetables with a value.

Calories: Onions: 40 kcal
median: 32 kcal
Protein: Onions: 1.1 g
median: 1.8 g
Carbs: Onions: 9.3 g
median: 6.9 g
Fat: Onions: 0.1 g
median: 0.3 g
Fiber: Onions: 1.7 g
median: 2.2 g

Vitamins and minerals

Nutrient	Per 100 g	%DV	Per 1 medium (110 g)	%DV
Saturated fat	0 g	<1%	0 g	<1%
Trans fat	0 g	no DV	0 g	no DV
Cholesterol	0 mg	0%	0 mg	0%
Sodium	4 mg	<1%	4.4 mg	<1%
Vitamin D	0 µg	0%	0 µg	0%
Calcium	23 mg	2%	25 mg	2%
Iron	0.21 mg	1%	0.23 mg	1%
Potassium	146 mg	3%	161 mg	3%
Vitamin A (RAE)	0 µg	0%	0 µg	0%
Vitamin C	7.4 mg	8%	8.1 mg	9%
Vitamin E	0.02 mg	<1%	0.02 mg	<1%
Vitamin K	0.4 µg	<1%	0.44 µg	<1%
Thiamin (B1)	0.05 mg	4%	0.05 mg	4%
Riboflavin (B2)	0.03 mg	2%	0.03 mg	2%
Niacin (B3)	0.12 mg	1%	0.13 mg	1%
Vitamin B6	0.12 mg	7%	0.13 mg	8%
Folate (approx.)	19 µg	5%	21 µg	5%
Vitamin B12	0 µg	0%	0 µg	0%
Phosphorus	29 mg	2%	32 mg	3%
Magnesium	10 mg	2%	11 mg	3%
Zinc	0.17 mg	2%	0.19 mg	2%
Selenium	0.5 µg	1%	0.55 µg	1%
Copper	0.04 mg	4%	0.04 mg	5%
Manganese	0.13 mg	6%	0.14 mg	6%

Source: U.S. Department of Agriculture, FoodData Central, FDC ID 170000 (SR Legacy, April 2018 final release). Values per 100 g as published in that record, imported 2026-03-13; serving weights from the same record, retrieved 2026-10-13.

% Daily Value: FDA Daily Values (2016 Nutrition Facts label rule, 21 CFR 101.9), adults and children 4+. Ranks compare the foods of the same category on this site. How we calculate.

Last updated 2026-10-13. Values are averages for the food as described; brands, varieties and cooking change them. Not medical advice.