Red Onion which is known to be high in fiber, potassium and vitamin C can be had in both raw as well as cooked form. The number of calories in this vegetable varies based on this factor. One tablespoon of chopped raw red onions weighing around 10 grams contains 4 calories. The total carbohydrate content in an equal quantity of raw red onion is 0.9 grams, dietary fiber content is 0.2 grams, sugar content is 0.4 grams and protein content is 0.1 gram.
1 oz raw yields of red onion contain a total of 11 calories out of which 90% calories are obtained from carbohydrates, 8% calories come from protein and 2% calories come from fat. The total fat content in it is 0.02 grams of which 0.007 gram is saturated fat content, 0.016 gram is polyunsaturated fat content and 0.006 gram is monounsaturated fat content.
The total sodium and potassium content in it is 1 mg and 37 mg respectively. Carbohydrate content in an equal serving of raw yields of red onion is 2.63 grams, dietary fiber content in it is 0.4 grams, sugar content is 1.11 grams and protein content in it is 0.24 gram. A thin slice of raw red onion contains 4 calories, medium raw slice contains 6 calories, large raw slice has 16 calories and one cup raw sliced red onions contain a total of 48 calories.
Red Onions are also preferred in their cooked form. 1 oz of cooked whole medium red onion contains 12.47 calories. The total fat content in it is 0.05 gram, saturated fat content in it is 0.01 gram, sodium content in it is 0.85 mg, carbohydrate content is 2.88 grams, dietary fiber content is 0.4 gram, sugar content is 1.34 grams and protein content is 0.39 grams. It also contains some amount of vitamin A, vitamin C and certain other essential vitamins.