How Many Calories Are In A Tomato? | What The USDA Shows

You’ve probably sliced a tomato onto a sandwich or tossed cherry tomatoes into a salad without giving their calorie count much thought. Maybe you’ve even wondered if that bright red orb counts as a fruit or a vegetable for diet tracking — and whether it secretly packs more calories than it looks.

The short answer is that tomatoes are remarkably low in calories, but the exact number changes with size, variety, and whether you eat them raw or cooked. This article breaks down the calorie counts by serving, explains how tomatoes fit into a low-calorie eating plan, and touches on the nutrients that make them worth adding to your plate.

Tomato Calories By Size And Serving

A medium raw tomato (about the size of a tennis ball) weighs roughly 123 grams and delivers about 22 calories. That comes from around 5 grams of carbohydrates, 1 gram of protein, and virtually no fat. Small tomatoes, around 91 grams, provide about 16 calories.

For a more standard reference, a 100-gram serving of raw tomato — roughly two-thirds of a medium fruit — contains about 18 calories. That makes it comparable to other water-rich vegetables like cucumber or zucchini. A single thin slice, the kind you’d put on a deli sandwich, contributes only about 3 calories, so piling on extra slices has almost no impact on your daily total.

Cherry or grape tomatoes are slightly denser by weight because of their higher skin-to-flesh ratio, but the difference is minimal: a cup of cherry tomatoes (about 149 grams) runs around 27 calories. Roma tomatoes, which are meatier and less watery, come in at roughly the same calorie density.

Why The Calorie Question Matters For Your Diet

Many people assume that any food with natural sugar must be moderately high in calories, but tomatoes disprove that. Their secret is water: about 95% of a raw tomato is water, which dilutes the energy content without sacrificing bulk. That makes them useful for adding volume to meals without pushing your calorie budget.

• Water content keeps calories low: Because tomatoes are roughly 95% water, you can eat a generous portion for very few calories. That water also contributes to hydration and helps you feel full.
• Tomatoes offer more than just low calories: They are a good source of vitamin C, potassium, iron, and folate — nutrients that support immune function, muscle contraction, and red blood cell production.
• Lycopene’s antioxidant role: This plant compound is one of the most potent antioxidants among dietary carotenoids. It may help lower LDL cholesterol and blood pressure, though the effects are most noticeable when tomatoes are eaten regularly as part of a balanced diet.
• Cooking concentrates nutrients but not calories: Tomato sauce, paste, and canned tomatoes have similar calorie densities to raw tomatoes per weight (about 18–20 calories per 100 grams for plain versions), but they pack more lycopene because heat releases it from cell walls.
• Varieties differ slightly: Cherry, Roma, and beefsteak tomatoes all fall within the same calorie range — roughly 16–25 calories per medium serving. The difference is small enough that you can choose based on taste and texture without worrying about the calorie count.

When people ask how many calories are in a tomato, the answer almost always comes back to the same number — about 18–22 per standard serving — no matter which variety they grab from the produce aisle.

Comparing Tomato Nutrition: Raw Vs. Cooked

Raw tomatoes are mostly water and simple carbs, while cooked tomatoes lose water and concentrate flavor. For a full breakdown of a medium tomato’s macronutrients, the USDA tomato nutrition page lists 1 gram of protein, 5 grams of carbohydrates (1 gram fiber, 3 grams sugar), and 0 grams of fat per 123-gram serving. That profile stays consistent whether you eat the tomato raw or gently cooked, as long as you don’t add oil or sugar.

Tomato Form	Calories	Key Nutritional Notes
Medium raw (123g)	22	95% water, 5g carbs, 1g protein, 0g fat
Small raw (91g)	16	Same proportional composition
100g raw	18	Standard reference serving
1 cup cherry tomatoes (149g)	~27	Slightly higher density due to skin
1 cup plain tomato sauce (245g)	~78	More concentrated calories, higher lycopene

Cooking tomatoes reduces their water content, so the same weight of cooked tomato contains fewer grams of water and proportionally more of everything else. That means a cup of tomato sauce carries about three to four times the calories of a cup of raw diced tomatoes, but still very few compared to most sauces.

How Tomatoes Fit Into A Low-Calorie Eating Plan

Because tomatoes are so low in calories, they work well as a volume booster — you can add them to dishes without significantly raising the calorie count. Here are several ways to use them strategically.

1. Use tomatoes as a base for low-calorie sauces: Blend raw tomatoes or roast them with herbs, then simmer to create a sauce that adds flavor for around 18–22 calories per half-cup (no added oil or sugar).
2. Pair with healthy fats for better lycopene absorption: Lycopene is fat-soluble, so eating tomatoes with a small amount of avocado, olive oil, or nuts may help your body absorb more of the compound. This doesn’t change the calorie count of the tomato itself, so you decide whether the added fat fits your goals.
3. Be mindful of processed tomato products: Canned tomato soup, ketchup, and pizza sauce often contain added sugars and oils that push the calorie count much higher than raw tomatoes. Check the label: a typical tablespoon of ketchup has about 15–20 calories, mostly from sugar.
4. Use weight instead of volume for accuracy: A “medium” tomato can vary from 110 to 140 grams. If you’re tracking calories closely, weighing the tomato gives you a precise count — roughly 0.18 calories per gram for raw tomato.
5. Incorporate them as snacks: Cherry tomatoes with a pinch of salt make a 25–30 calorie snack that provides vitamin C and antioxidants, easily fitting into even the tightest eating plan.

The takeaway is that tomatoes are one of the most forgiving foods for calorie counters. You’d have to eat several pounds to worry about the number, so enjoy them freely within your recommended vegetable intake.

The Health Benefits Beyond The Calories

Tomatoes bring more than just a low calorie count to the table. They are a good source of several vitamins and minerals, and they contain lycopene — a compound that has been studied for its antioxidant properties. A review hosted by Healthline examined the nutrients in raw tomatoes — the calories per 100g page also discusses lycopene’s role in reducing oxidative stress and its association with lower risks of certain chronic diseases.

Health Aspect	Key Benefit
Antioxidant support	Lycopene is one of the most potent antioxidants among dietary carotenoids, helping neutralize free radicals.
Heart health	Dietary intake of tomatoes and tomato products has been associated with a decreased risk of cardiovascular disease in some studies.
Blood pressure and cholesterol	Regular consumption of tomatoes may help lower LDL cholesterol and blood pressure, per observational research.

These benefits appear to work best when lycopene is consumed alongside the other phytonutrients naturally present in tomatoes. While no single food is a magic bullet, adding tomatoes to a varied diet is a simple, low-calorie way to increase your intake of protective plant compounds.

The Bottom Line

A medium tomato contains about 22 calories, making it an excellent addition to any eating plan that aims to keep calories low while maximizing nutrients. The calorie count varies only slightly by size or variety, and the water content ensures you can eat a generous portion without guilt. For the health benefits tied to lycopene, including tomatoes regularly — whether raw, cooked, or in minimally processed forms — may offer modest cardiovascular and antioxidant support as part of an overall balanced diet.

Your local market’s produce section likely carries several tomato sizes — using a kitchen scale to weigh them gives you the most accurate calorie count for your specific tomato of choice.