Tomato Slice Calories: Exact Count Per Slice Revealed

A single medium tomato slice (approximately 1/8 inch thick or 5g) contains just 1-2 calories, making tomatoes one of the lowest-calorie vegetables you can add to your diet while still gaining valuable nutrients and flavor.

Understanding Tomato Slice Calorie Content

When tracking your daily calorie intake, knowing the precise nutritional value of common food additions like tomato slices matters. Based on the most recent USDA FoodData Central measurements, raw tomatoes contain approximately 18 calories per 100 grams. But how does this translate to actual slices you'd add to sandwiches, salads, or burgers?

The exact calorie count depends on slice thickness and tomato variety. A standard medium slicing tomato (about 123g) yields approximately 22 calories total. When sliced into eight equal pieces, each slice contains roughly 1-2 calories. This minimal calorie contribution makes tomatoes an excellent choice for those monitoring their intake without sacrificing flavor or nutrition.

Tomato Measurement	Calories	Carbohydrates	Key Nutrients
1 medium slice (5g)	1-2	0.3g	Vitamin C, lycopene
1 cup chopped (180g)	32	7g	Vitamin A, potassium
1 medium whole tomato (123g)	22	5g	Vitamin K, folate
1 Roma tomato (60g)	11	2.5g	Higher lycopene concentration

Why Calorie Counts Vary Slightly Between Tomato Varieties

Not all tomatoes are nutritionally identical. The calorie content per slice can vary based on several factors:

• Water content - Tomatoes with higher water content (like beefsteak varieties) have slightly fewer calories per gram
• Ripeness level - Riper tomatoes contain marginally more natural sugars
• Tomato variety - Roma tomatoes have less water and slightly more concentrated nutrients
• Slice thickness - A thicker slice naturally contains more tomato material

According to research published in the Journal of Food Composition and Analysis, the difference between common tomato varieties rarely exceeds 5% in calorie content. For practical diet tracking purposes, you can safely estimate 1-2 calories per standard slice without significant error.

Nutritional Value Beyond Calories

While the calorie count is impressively low, tomatoes offer substantial nutritional benefits that make them valuable beyond just calorie counting:

Tomatoes are particularly rich in lycopene, a powerful antioxidant that gives tomatoes their red color. Research from the Harvard T.H. Chan School of Public Health indicates that lycopene may help reduce the risk of heart disease and certain cancers. Interestingly, cooking tomatoes actually increases lycopene bioavailability, though raw slices still provide significant amounts.

Each tomato slice also contributes:

• Small amounts of vitamin C (about 3% of daily value per slice)
• Traces of vitamin A and potassium
• Hydration benefits (tomatoes are 95% water)
• Dietary fiber that supports digestive health

Practical Applications for Diet Tracking

Understanding the minimal calorie impact of tomato slices can help you make informed decisions in various dietary contexts:

For Weight Management

Adding tomato slices to sandwiches instead of higher-calorie options like cheese or avocado can save significant calories without sacrificing volume or satisfaction. Three slices add only 3-6 calories while providing texture, moisture, and nutrients.

For Diabetic Meal Planning

With just 0.3g of carbohydrates per slice, tomatoes have minimal impact on blood sugar. The American Diabetes Association recommends tomatoes as a non-starchy vegetable that can be consumed freely by people managing diabetes.

For Low-FODMAP Diets

According to Monash University's FODMAP diet research, tomatoes are low-FODMAP in servings of 75g (about 6 slices), making them suitable for those managing IBS symptoms.

Common Misconceptions About Tomato Calories

Several myths persist about tomato nutrition that deserve clarification:

• "All tomatoes have the same calorie count" - While differences are small, cherry tomatoes have slightly more calories per gram than larger varieties due to lower water content
• "Cooked tomatoes have more calories" - Cooking doesn't increase calories, though it may concentrate nutrients by removing water
• "Organic tomatoes have fewer calories" - Organic status doesn't affect calorie content, though it may impact other nutritional aspects

When tracking calories for dietary purposes, focus on the actual weight or volume rather than assuming all tomato slices are identical. A kitchen scale provides the most accurate measurement for precise diet tracking.

Maximizing Tomato Benefits in Your Diet

To get the most nutritional value from tomato slices while keeping track of calories:

• Add slices to sandwiches instead of higher-calorie spreads
• Use as a colorful, low-calorie pizza topping
• Create layered salads with multiple tomato varieties
• Add to omelets for flavor without significant calorie increase
• Pair with healthy fats like olive oil to enhance lycopene absorption

Remember that the preparation method affects the overall calorie count. While plain tomato slices are extremely low-calorie, adding dressings, oils, or cheese significantly increases the total. For accurate tracking, always account for all components of your dish.

How many calories are in one slice of tomato?

A single medium tomato slice (approximately 1/8 inch thick or 5g) contains 1-2 calories. This minimal calorie count makes tomatoes an excellent low-calorie addition to various dishes.

Do different tomato varieties have different calorie counts?

Yes, but the differences are minimal. Beefsteak tomatoes have slightly fewer calories per gram due to higher water content, while Roma and cherry tomatoes have marginally more concentrated nutrients. The variation between common varieties rarely exceeds 5%.

Does the ripeness of a tomato affect its calorie content?

Slightly. Riper tomatoes contain marginally more natural sugars, which can increase calories by about 5-10% compared to less ripe counterparts. However, this difference is minimal in practical terms for dietary tracking purposes.

Are tomato slices suitable for low-carb diets?

Yes, tomato slices are excellent for low-carb diets. Each slice contains only about 0.3g of carbohydrates, making them suitable even for strict keto diets when consumed in reasonable quantities.

Does cooking tomatoes change their calorie content?

Cooking doesn't significantly change the calorie content of tomatoes, though it may concentrate nutrients by removing water. The main nutritional benefit of cooking tomatoes is increased lycopene bioavailability, not calorie changes.