Calories in Tomatoes: Nutrition Facts & Serving Sizes
Per 1 medium (123g)
Per 100g
Source: USDA FoodData Central, SR Legacy, March 2026.
One medium tomato (123g) contains about 28 calories with 1.5g of protein, 6.3g of carbs, and 0.2g of fat. Per 100g, tomatoes provide just 23 calories, making them one of the lowest-calorie whole foods available. Tomatoes are technically a fruit but are used almost exclusively as a vegetable in cooking. The standout micronutrient is vitamin C at 23.4mg per 100g, which works out to about 29mg per medium tomato. Tomatoes are also a source of potassium at 204mg per 100g and vitamin A at 32mcg per 100g. They contain lycopene, a carotenoid antioxidant that is best absorbed from cooked or processed tomato products. For anyone looking to add volume to meals without adding many calories, tomatoes are one of the best options out there. Slice them, dice them, or cook them down into a sauce for basically zero caloric cost.
Nutrition Highlights
Calories by Serving Size
| Serving | Cal | Protein | Carbs | Fat | Fiber |
|---|---|---|---|---|---|
| 1 medium (123g) | 28.3 | 1.5g | 6.3g | 0.2g | 1.4g |
| 1 small (91g) | 20.9 | 1.1g | 4.6g | 0.2g | 1g |
| 1 large (182g) | 41.9 | 2.2g | 9.3g | 0.4g | 2g |
| 1 cup (180g) | 41.4 | 2.2g | 9.2g | 0.4g | 2g |
| 1 slice or wedge (20g) | 4.6 | 0.2g | 1g | 0g | 0.2g |
| 100g | 23 | 1.2g | 5.1g | 0.2g | 1.1g |
Track Tomato in CaloBurner
Snap a photo to log calories and macros instantly.
Full Nutrition Facts (per 100g)
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Calories | 23 | 1% |
| Protein | 1.2g | 2% |
| Total Fat | 0.2g | |
| Total Carbohydrates | 5.1g | 2% |
| Dietary Fiber | 1.1g | 4% |
| Sugars | 4g | 8% |
| Sodium | 13mg | 1% |
Vitamins & Minerals (per 100g)
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Calcium | 13mg | 1% |
| Iron | 0.5mg | 3% |
| Potassium | 204mg | 4% |
| Vitamin A | 32mcg | 4% |
| Vitamin C | 23.4mg | 26% |
| Vitamin B6 | 0.1mg | 6% |
| Magnesium | 10mg | 2% |
| Phosphorus | 28mg | 2% |
| Zinc | 0.1mg | 1% |
| Selenium | 0.4mcg | 1% |
| Folate | 9mcg | 2% |
| Thiamin (B1) | 0.1mg | 8% |
| Niacin (B3) | 0.5mg | 3% |
% Daily Values based on a 2,000 calorie diet (FDA reference).
Health Benefits of Tomatoes
Tomatoes are a high-volume, low-calorie food with a solid micronutrient profile. The 23.4mg of vitamin C per 100g covers about 26% of the daily recommended intake for adults. Vitamin C supports immune function, collagen synthesis, and non-heme iron absorption. Adding tomatoes to a meal with plant-based iron sources (lentils, spinach) improves how much iron you absorb.
The 32mcg of vitamin A per 100g (from beta-carotene) supports vision, skin health, and immune function. Tomatoes are also one of the primary dietary sources of lycopene. While raw tomatoes contain lycopene, it becomes significantly more bioavailable when cooked or processed (as in tomato sauce, paste, or juice). If you want the lycopene benefits, cooked tomato products are more effective.
Potassium at 204mg per 100g contributes to electrolyte balance, blood pressure regulation, and muscle function. For those training hard and sweating a lot, getting adequate potassium is important for muscle recovery and preventing cramps.
At 1.1g of fiber per 100g, tomatoes are not a major fiber source, but eating a few tomatoes throughout the day still adds up. The fiber, combined with the high water content (tomatoes are about 94% water), contributes to satiety at a very low calorie cost.
Dietary Considerations
Tomatoes are naturally gluten-free, vegan, dairy-free, paleo, Whole30 compliant, and keto-friendly. With only 5.1g of carbs per 100g and 1.1g of fiber (leaving 4g net carbs), tomatoes are compatible with most low-carb approaches. For weight loss, tomatoes are a volume-eating staple: a whole large tomato (182g) has only 42 calories and can fill a plate or bowl. Some individuals with acid reflux or GERD may find that tomatoes trigger symptoms due to their acidity. If that is you, try cooking them, which can reduce acidity slightly.
Daily Intake (100g)
100g of tomato provides 1% of a 2,000-calorie diet.
Track Your Intake
See how tomato fits your personal calorie and macro targets.
Related Foods
Restaurant Meals with Tomato
See how tomato shows up in popular restaurant dishes.
Frequently Asked Questions
How many calories in a tomato?
One medium tomato (123g) has about 28 calories. A small tomato (91g) has about 21 calories, and a large tomato (182g) has about 42 calories. Per 100g, tomatoes contain 23 calories. They are one of the lowest-calorie whole foods you can eat.
Is tomato good for weight loss?
Yes, tomatoes are great for weight loss. At only 23 calories per 100g and with a high water content, they add volume and flavor to meals without meaningfully increasing your calorie intake. They work well in salads, omelets, stir-fries, and on sandwiches.
How much protein in a tomato?
Tomatoes contain 1.2g of protein per 100g. One medium tomato (123g) provides about 1.5g of protein. Tomatoes are not a protein source. They are primarily a low-calorie vegetable valued for their micronutrients and antioxidants, not their protein content.
Are tomatoes keto-friendly?
Yes, tomatoes can fit into a keto diet in moderate amounts. Per 100g, they have 5.1g of total carbs and 1.1g of fiber, leaving 4g of net carbs. One medium tomato has about 5g of net carbs. Stick to one or two tomatoes per meal and track your total carb intake.
Are tomatoes a fruit or a vegetable?
Botanically, tomatoes are a fruit because they develop from a flower and contain seeds. Culinarily and nutritionally, they are almost always grouped with vegetables. For tracking purposes, treat them like a vegetable since they are savory, low in sugar, and used in savory dishes.
What is the best way to get lycopene from tomatoes?
Cooked and processed tomato products (tomato sauce, paste, juice, soup) provide more bioavailable lycopene than raw tomatoes. Cooking breaks down cell walls and makes lycopene easier for your body to absorb. Adding a small amount of healthy fat (like olive oil) alongside cooked tomatoes further improves lycopene absorption since it is fat-soluble.
Track Tomatoes in Your Diet
Snap a photo of your meal and CaloBurner will calculate the exact calories and macros. No food weighing required.