There are about 40 calories in 100 grams of onion.
The Ministry of Health's table lists 29 entries for onion, from 28 to 366 calories per 100 grams. The number here is for Onion, raw, the entry that stands for the food on this page.
How many calories are in a portion of onion?
A weight in grams, or one of the food's own units, works out the calories and nutrients of that portion.
- Calories
- 40
- Protein
- 1.1 g
- Fat
- 0.1 g
- Carbohydrates
- 7.6 g
- Sodium
- 4 mg
Onion comes in these common portions, with the calories of each.
| Portion | Weight | Calories | Protein | Fat | Carbohydrates |
|---|---|---|---|---|---|
| small unit | 64 g | 26 | 0.7 | 0.06 | 4.9 |
| medium unit | 117 g | 47 | 1.3 | 0.12 | 8.9 |
| large unit | 162 g | 65 | 1.8 | 0.16 | 12.3 |
| tablespoon | 12 g | 5 | 0.13 | 0.01 | 0.91 |
| teaspoon | 5 g | 2 | 0.06 | 0.01 | 0.38 |
| medium slice | 14 g | 6 | 0.15 | 0.01 | 1.1 |
100 grams of onion contain 1.1 grams of protein, 0.1 grams of fat and 7.6 grams of carbohydrates.
- Protein1.1 g
- Fat0.1 g
- Saturated fat0.04 g
- Carbohydrates7.6 g
- Sugars4.2 g
- Dietary fibre1.7 g
- Sodium4 mg
- Cholesterol0 mg
These vitamins and minerals are in 100 grams of onion, as the Ministry lists them.
- Calcium
- 23 mg
- Iron
- 0.21 mg
- Potassium
- 146 mg
- Magnesium
- 10 mg
- Zinc
- 0.17 mg
- Vitamin C
- 7.4 mg
- Folate
- 19 mcg
The Ministry of Health lists 29 entries for onion.
The numbers are per 100 grams. Brands, ways of cooking and sizes each have a row of their own.
All 29 entries in the table
| Entry | Calories | Protein | Fat | Carbohydrates |
|---|---|---|---|---|
| Onion, green (spring/scallions), raw | 32 | 1.8 | 0.2 | 4.7 |
| Onion, rawThe entry used above | 40 | 1.1 | 0.1 | 7.6 |
| Onion, green, with roots (roots not eaten) | 31 | 1.8 | 0.2 | 7 |
| Onions, mature, cooked, from fresh, fat not added | 44 | 1.4 | 0.2 | 8.7 |
| Onions, mature, cooked, from frozen, fat not added | 28 | 0.7 | 0.1 | 5 |
| Onions, pearl, cooked, NS as to form | 44 | 1.4 | 0.2 | 8.7 |
| Onions, pearl, cooked, from fresh | 44 | 1.4 | 0.2 | 8.7 |
| Onions, pearl, cooked, from frozen | 28 | 0.7 | 0.1 | 5.3 |
| Onions, pearl, canned | 38 | 1 | 0.2 | 8 |
| Onions, young green, cooked, NS as to form, fat not added | 33 | 1.9 | 0.2 | 5 |
| Onions, dehydrated | 349 | 8.9 | 0.5 | 74.1 |
| Onion, fried in canola oil | 144 | 1.6 | 9.9 | 11.1 |
| Onion, fried in olive oil | 144 | 1.6 | 9.9 | 11.1 |
| Onion, fried, dry, Osem | 366 | 10.5 | 7.9 | 56.7 |
| Onion, fried in corn oil | 146 | 1.6 | 9.9 | 11.1 |
| Onion, fried in soy oil | 144 | 1.6 | 9.9 | 11.1 |
| Onion, fried in sunflower oil | 144 | 1.6 | 9.9 | 11.1 |
| Onion, fried in butter | 130 | 1.7 | 8.1 | 11.2 |
| Onion, fried in margarine | 111 | 1.6 | 6 | 11.1 |
| Onion, dried, baked with soy oil | 145 | 1.6 | 10 | 11 |
| Onion, stuffed with rice in tomato paste, with soy oil | 91 | 1.5 | 3.9 | 11.7 |
| Onion, stuffed with rice and beef in tomato paste and soy oil | 131 | 5 | 6.3 | 12.5 |
| Onion, cooked, with canola oil | 144 | 1.6 | 9.8 | 11.1 |
| Onions, cooked, boiled, drained, without salt, fat not added | 44 | 1.4 | 0.2 | 10.1 |
| Shallots, fresh | 72 | 2.5 | 0.1 | 16.8 |
| Onion, frozen, chopped, Sunfrost | 31 | 1.4 | 0.2 | 6.5 |
| Onion, stuffed with rice and tomato paste with canola oil | 91 | 1.5 | 3.9 | 11.7 |
| Onion, stuffed with rice and beef, in tomato paste and canola oil | 128 | 5 | 6.3 | 12.3 |
| Onion, fried, fat not added | 65 | 1.8 | 0.2 | 12.3 |
These foods are close to onion in calories.
- Pepper, hot chili, red or green, fresh40 calories per 100 g
- Juice, carrot40 calories per 100 g
- Brussels sprouts, raw, with stems39 calories per 100 g
- Pumpkin40 calories per 100 g
- Brussels sprouts, frozen, uncooked39 calories per 100 g
- Bitter melon leaves, horseradish leaves, jute leaves, or radish leaves, cooked, fat not added41 calories per 100 g
These are the questions people ask about the calories in onion.
How many calories are in onion?
100 grams of onion have about 40 calories. The Ministry of Health's table lists 29 entries for it, from 28 to 366 calories per 100 grams.
How many calories are in 50, 100 and 200 grams of onion?
50 grams have 20 calories, 100 grams have 40 and 200 grams have 80.
How much protein, fat and carbohydrates are in onion?
In 100 grams there are 1.1 g of protein, 0.1 g of fat and 7.6 g of carbohydrates, of which 4.2 g are sugars.
How many calories are in one medium slice of onion?
The Ministry's table gives 14 grams for one medium slice of onion, which is 6 calories.
The foods, their nutrients and their unit weights are the national nutrition table of the Ministry of Health, read on 5 November 2026. The figures are averages per 100 grams of the food as the table lists it.