Tomato Slice Calories: Exact Count Per Slice (2.5 Calories)

A single average tomato slice (approximately 15g) contains about 2.5 calories. This precise measurement comes from USDA FoodData Central, the most authoritative source for nutritional information in the United States.

Understanding the exact calorie content of everyday ingredients like tomato slices matters more than you might think. Whether you're tracking macros for weight management, planning diabetic-friendly meals, or simply curious about what you're consuming, accurate nutritional data forms the foundation of informed eating decisions. As someone who's worked with both professional chefs and home cooks for over 15 years, I've seen how small miscalculations in ingredient calories can significantly impact overall meal planning.

Why Tomato Slice Calories Matter in Your Daily Diet

Tomatoes appear in countless dishes—from salads and sandwiches to sauces and salsas—making their precise nutritional profile essential knowledge. Unlike many vegetables that dramatically change in calorie density when processed, raw tomatoes maintain remarkably consistent nutritional properties whether sliced, diced, or whole. This consistency makes them a reliable component in calorie-conscious meal planning.

Breaking Down Tomato Nutrition: Beyond Just Calories

While calories often dominate nutritional conversations, tomatoes offer impressive nutritional value beyond their minimal caloric footprint. A standard tomato slice delivers more than just negligible energy:

Nutrient	Per Slice (15g)	Daily Value %
Calories	2.5	<1%
Carbohydrates	0.6g	<1%
Fiber	0.2g	1%
Vitamin C	2.5mg	3%
Vitamin A	100 IU	2%
Lycopene	0.7mg	-

This nutritional breakdown comes directly from USDA FoodData Central, the gold standard for nutritional information in the United States. The data reflects raw, red tomatoes of standard commercial varieties as commonly found in grocery stores.

How Tomato Size Affects Calorie Counting Accuracy

One critical factor many overlook is that "tomato slice" isn't a standardized measurement. The actual calorie content varies based on:

• Tomato variety - Roma tomatoes have slightly different density than beefsteak varieties
• Slice thickness - A 1/4" slice versus 1/2" slice changes weight significantly
• Tomato size - Small cherry tomatoes versus large heirloom varieties

According to research published in the Journal of Food Composition and Analysis, modern commercial tomato varieties have maintained relatively consistent nutritional profiles over the past two decades despite changes in growing practices. This stability means the calorie information you find today remains applicable to tomatoes purchased at your local market.

Tomato Slices vs. Other Tomato Forms: Calorie Comparison

Understanding how preparation methods affect calorie density helps make smarter dietary choices. Here's how common tomato preparations compare:

Tomato Form	Portion Size	Calories	Key Differences
Raw slice	15g (1 slice)	2.5	Maximum water content, minimal processing
Cherry tomato	1 small (17g)	3	Slightly higher sugar content than standard slices
Canned diced	100g	18	Often contains added salt or calcium chloride
Tomato paste	30g (2 tbsp)	35	Concentrated form with significantly higher calorie density

This comparison demonstrates why understanding preparation methods matters. While fresh tomato slices remain one of the lowest-calorie vegetable options available, processed tomato products can contain substantially more calories per serving due to water removal and concentration of natural sugars.

Practical Applications: Using Tomato Slices in Meal Planning

With their negligible calorie count and impressive nutrient profile, tomato slices offer tremendous versatility in various dietary approaches:

• Weight management - Add volume to sandwiches and salads without significant calorie impact
• Diabetic meal planning - Low glycemic impact with beneficial fiber content
• Hydration support - 95% water content helps meet daily fluid requirements
• Flavor enhancement - Provides umami and acidity without added fats or sugars

Professional chefs consistently use tomatoes as a "calorie dilution" ingredient—adding substantial flavor and volume while minimally impacting the overall calorie count of dishes. This technique works particularly well in sauces, stews, and casseroles where tomatoes can replace higher-calorie thickeners.

Common Misconceptions About Tomato Calories

Despite their simplicity, several myths persist about tomato nutrition:

• "All tomatoes have the same calorie count" - While generally consistent, heirloom varieties can vary by up to 15% in caloric density
• "Cooking significantly changes tomato calories" - Water loss concentrates nutrients but doesn't substantially change total calories per serving
• "Organic tomatoes have fewer calories" - Growing method doesn't affect caloric content, only potential pesticide residues

These misconceptions often lead to inaccurate tracking, particularly for those meticulously monitoring their intake. The reality is that fresh tomato slices represent one of the most consistently low-calorie vegetable options available year-round.

Tracking Tomato Calories in Real-World Scenarios

When planning meals, consider these practical examples:

• A standard deli sandwich with 3-4 tomato slices adds only 7-10 calories
• A large garden salad with 10-12 slices contributes approximately 25-30 calories
• Homemade salsa with 1 diced tomato (about 8 slices) contains roughly 20 calories

These minimal additions provide significant nutritional benefits without compromising calorie goals. The fiber content also promotes satiety, potentially reducing overall calorie consumption during meals.

Conclusion: Tomatoes as a Nutritional Powerhouse

While a single tomato slice contains just 2.5 calories, its nutritional contribution extends far beyond this minimal energy value. The combination of vitamins, antioxidants, and hydration benefits makes tomatoes an exceptionally valuable component of any balanced diet. Understanding the precise calorie content allows for accurate tracking while appreciating their broader nutritional profile helps maximize their dietary benefits. Whether you're counting calories meticulously or simply eating mindfully, tomatoes offer remarkable nutritional value with virtually no caloric cost.

How many calories are in one medium tomato slice?

A single average tomato slice (approximately 15g) contains about 2.5 calories according to USDA FoodData Central measurements.

Do different tomato varieties have different calorie counts?

Most common commercial tomato varieties have very similar calorie counts, typically varying by no more than 10-15% between types. Roma, beefsteak, and vine-ripened tomatoes all contain approximately 2.5 calories per 15g slice.

Does the thickness of a tomato slice affect its calorie content?

Yes, thicker slices contain more tomato material and therefore more calories. A standard 1/4-inch slice (15g) has about 2.5 calories, while a thicker 1/2-inch slice (30g) would contain approximately 5 calories.

Are tomato slices good for weight loss?

Tomato slices are excellent for weight loss diets due to their extremely low calorie density (2.5 calories per slice), high water content (95%), and fiber content which promotes satiety. They add volume and nutrients to meals with minimal caloric impact.

How does the calorie content of tomato slices compare to other common vegetables?

Tomato slices (2.5 calories per 15g) are among the lowest-calorie vegetable options, comparable to cucumbers (2 calories per 15g) and zucchini (3 calories per 15g), but lower than carrots (5 calories per 15g) or bell peppers (4 calories per 15g).