Onion vs. Tomato
Nutrition comparison of Onion and Tomato
Ever wonder how your favorite foods stack up against each other in terms of nutrition?
We compared the nutritional contents of
onion
versus
tomato
(100g each)
below using 2020 USDA and NIH data[1].
For a quick recap of significant nutrients and differences in onion and tomato:
- Tomato has 55% less calories than onion.
- Tomato has more niacin.
- Tomato is a great source of Vitamin C and potassium.
USDA sources for nutritional information: Onion (Onions, raw) and Tomato (Tomatoes, red, ripe, raw, year round average) . Have a correction or suggestions? Shoot us an email.
Calories and Carbs
calories
Tomato has 55% less calories than onion - onion has 40 calories per 100 grams and tomato has 18 calories.
For macronutrient ratios, onion is lighter in protein, heavier in carbs and lighter in fat compared to tomato per calorie. Onion has a macronutrient ratio of 10:88:2 and for tomato, 17:74:9 for protein, carbohydrates and fat from calories.
Macro Ratios from Calories:
| Onion | Tomato | |
|---|---|---|
| Protein | 10% | 17% |
| Carbohydrates | 88% | 74% |
| Fat | 2% | 9% |
| Alcohol | ~ | ~ |
carbohydrates
Onion and tomato contain similar amounts of carbs - onion has 9.3g of total carbs per 100 grams and tomato has 3.9g of carbohydrates.
dietary fiber
Onion has 42% more dietary fiber than tomato - onion has 1.7g of dietary fiber per 100 grams and tomato has 1.2g of dietary fiber.
sugar
Onion and tomato contain similar amounts of sugar - onion has 4.2g of sugar per 100 grams and tomato has 2.6g of sugar.
Protein
protein
Onion and tomato contain similar amounts of protein - onion has 1.1g of protein per 100 grams and tomato has 0.88g of protein.
Fat
saturated fat
Both onion and tomato are low in saturated fat - onion has 0.04g of saturated fat per 100 grams and tomato has 0.03g of saturated fat.
Vitamins
Vitamin C
Tomato is a great source of Vitamin C and it has 85% more Vitamin C than onion - onion has 7.4mg of Vitamin C per 100 grams and tomato has 13.7mg of Vitamin C.
Vitamin A
Tomato has more Vitamin A than onion - tomato has 42ug of Vitamin A per 100 grams and onion does not contain significant amounts.
Vitamin E
Onion and tomato contain similar amounts of Vitamin E - onion has 0.02mg of Vitamin E per 100 grams and tomato has 0.54mg of Vitamin E.
Vitamin K
Onion and tomato contain similar amounts of Vitamin K - onion has 0.4ug of Vitamin K per 100 grams and tomato has 7.9ug of Vitamin K.
The B Vitamins
Tomato has more niacin. Both onion and tomato contain significant amounts of thiamin, riboflavin, pantothenic acid, Vitamin B6 and folate.
| Onion | Tomato | |
|---|---|---|
| Thiamin | 0.046 MG | 0.037 MG |
| Riboflavin | 0.027 MG | 0.019 MG |
| Niacin | 0.116 MG | 0.594 MG |
| Pantothenic acid | 0.123 MG | 0.089 MG |
| Vitamin B6 | 0.12 MG | 0.08 MG |
| Folate | 19 UG | 15 UG |
Minerals
calcium
Onion has 130% more calcium than tomato - onion has 23mg of calcium per 100 grams and tomato has 10mg of calcium.
iron
Onion and tomato contain similar amounts of iron - onion has 0.21mg of iron per 100 grams and tomato has 0.27mg of iron.
potassium
Tomato is a great source of potassium and it has 62% more potassium than onion - onion has 146mg of potassium per 100 grams and tomato has 237mg of potassium.
Antioxidants and Phytonutrients
flavonoids
Naturally occuring in fruits and vegetables, flavonoids are associated with many health benefits and used in a variety of medicinal and pharmaceutical applications. [2][3]
For specific flavonoid compounds, both onion and tomato contain small amounts of myricetin.
| Onion | Tomato | |
|---|---|---|
| apigenin | 0.01 mg | ~ |
| luteolin | 0.02 mg | ~ |
| isorhamnetin | 5.01 mg | ~ |
| kaempferol | 0.65 mg | 0.09 mg |
| myricetin | 0.03 mg | 0.13 mg |
| Quercetin | 20.3 mg | 0.58 mg |
carotenoids
Carotenoids are micronutrients commonly found in plants and some animal products. An example is beta-carotene, the notable carotenoid which is a popular source of Vitamin A.[4][5]
For specific types of carotenoids,
| Onion | Tomato | |
|---|---|---|
| beta-carotene | 1 UG | 449 UG |
| lutein + zeaxanthin | 4 UG | 123 UG |
| alpha-carotene | ~ | 101 UG |
| lycopene | ~ | 2573 UG |
Omega-3 and Omega-6
omega 3s
For omega-3 fatty acids, both onion and tomato contain small amounts of alpha linoleic acid (ALA).
| Onion | Tomato | |
|---|---|---|
| alpha linoleic acid | 0.004 G | 0.003 G |
| Total | 0.004 G | 0.003 G |
omega 6s
Comparing omega-6 fatty acids, tomato has more linoleic acid than onion per 100 grams.
| Onion | Tomato | |
|---|---|---|
| linoleic acid | 0.013 G | 0.08 G |
| Total | 0.013 G | 0.08 G |
Customize your serving size
The comparison below is by weight, but sometimes 100g isn't that intuitive of a measurement for food. View a custom portion comparison (e.g. cups, oz, package).
You can try adding or subtracting the amount of either Onion or Tomato .
Onion g
()
|
Daily Values (%) |
Tomato g
()
|
|||||
|---|---|---|---|---|---|---|---|
| KCAL % |
|
5% | calories | 5% |
|
KCAL % | |
| G % |
|
5% | carbohydrates | 5% |
|
G % | |
| G % |
|
5% | dietary fiber | 5% |
|
G % | |
| G | 5% | sugar | 5% | G | |||
| G % |
|
5% | total fat | 5% |
|
G % | |
| G % |
|
5% | saturated fat | 5% |
|
G % | |
| G | 5% | monounsaturated fat | 5% | G | |||
| G | 5% | polyunsaturated fat | 5% | G | |||
| G | 5% | trans fat | 5% | G | |||
| MG | 5% | cholesterol | 5% | MG | |||
| MG % |
|
5% | sodium | 5% |
|
MG % | |
| 5% | Vitamins and Minerals | 5% | |||||
| UG % |
|
5% | Vitamin A | 5% |
|
UG % | |
| MG % |
|
5% | Vitamin C | 5% |
|
MG % | |
| IU % |
|
5% | Vitamin D | 5% |
|
IU % | |
| MG % |
|
5% | calcium | 5% |
|
MG % | |
| MG % |
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5% | iron | 5% |
|
MG % | |
| MG % |
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5% | magnesium | 5% |
|
MG % | |
| MG % |
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5% | potassium | 5% |
|
MG % | |
| MG % |
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5% | thiamin (Vit B1) | 5% |
|
MG % | |
| MG % |
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5% | riboflavin (Vit B2) | 5% |
|
MG % | |
| MG % |
|
5% | niacin (Vit B3) | 5% |
|
MG % | |
| MG % |
|
5% | Vitamin B6 | 5% |
|
MG % | |
| MG % |
|
5% | pantothenic acid (Vit B5) | 5% |
|
MG % | |
| UG % |
|
5% | folate (Vit B9) | 5% |
|
UG % | |
| UG % |
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5% | Vitamin B12 | 5% |
|
UG % | |
| MG % |
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5% | Vitamin E | 5% |
|
MG % | |
| UG % |
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5% | Vitamin K | 5% |
|
UG % | |
| G % |
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5% | protein | 5% |
|
G % | |
| UG % |
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5% | biotin (Vit B7) | 5% |
|
UG % | |
| MG % |
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5% | choline | 5% |
|
MG % | |
| MG % |
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5% | chlorine | 5% |
|
MG % | |
| UG % |
|
5% | chromium | 5% |
|
UG % | |
| MG % |
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5% | copper | 5% |
|
MG % | |
| UG % |
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5% | fluoride | 5% |
|
UG % | |
| UG % |
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5% | iodine | 5% |
|
UG % | |
| MG % |
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5% | manganese | 5% |
|
MG % | |
| UG % |
|
5% | molybdenum | 5% |
|
UG % | |
| MG % |
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5% | phosphorus | 5% |
|
MG % | |
| UG % |
|
5% | selenium | 5% |
|
UG % | |
| MG % |
|
5% | zinc | 5% |
|
MG % | |
| G | 5% | Water | 5% | G | |||
| G | 5% | Starch | 5% | G | |||
| G | 5% | Alcohol | 5% | G | |||
FAQ
Does onion or tomato contain more calories in 100 grams?Tomato has 60% less calories than onion - onion has 40 calories in 100g and tomato has 18 calories.
Does onion or tomato have more carbohydrates?
By weight, onion and tomato contain similar amounts of carbs - onion has 9.3g of carbs for 100g and tomato has 3.9g of carbohydrates.