How Many Calories in a Tomato

A medium tomato contains about 22 calories, making it one of the most calorie-efficient vegetables (technically a fruit) you can eat. Most of the weight in a tomato is water and fibre, with very little fat or sugar. Even larger tomatoes only reach about 33–35 calories, while smaller ones — like cherry or grape tomatoes — contain around 3 to 5 calories each. This makes tomatoes ideal for low-calorie eating plans where volume and nutrition matter more than energy density.

Calories by Type and Size

Tomatoes vary slightly in calorie count depending on size and variety. A small tomato (about 100 grams) has roughly 18–20 calories, while a medium tomato (125–130 grams) offers about 22–25 calories. A large beefsteak tomato (up to 180 grams) can reach 35 calories. Cherry or grape tomatoes weigh only about 10–15 grams each, with 3–5 calories per tomato, making them a perfect snack for calorie control.

Nutritional Breakdown of a Tomato

A raw tomato is made up of about 95% water, with the rest primarily coming from carbohydrates and fibre. A medium tomato contains 4–5 grams of carbs, including 1.5 grams of sugar and 1.5 grams of fibre, plus less than 1 gram of protein and fat. Despite the low calorie count, tomatoes are high in vitamin C, potassium, folate, vitamin K, and lycopene, a powerful antioxidant linked to heart health, skin protection, and cancer prevention.

Low Calorie, High Volume: Why Tomatoes Help With Fat Loss

Tomatoes are a classic example of a high-volume, low-calorie food. Because they’re mostly water, you can eat a large portion without consuming many calories. This makes tomatoes a valuable tool for controlling hunger, especially when added to meals like salads, wraps, egg dishes, or grilled vegetables. Their mild sweetness and acidity also help replace high-calorie condiments or sauces with a fresher, lighter flavour profile.

Cooking vs Raw: Does It Change the Calories?

Cooking tomatoes doesn’t significantly change the calorie count unless oil, butter, or cheese is added. A 100-gram serving of stewed or roasted tomatoes still has under 40 calories, making them an excellent low-calorie base for sauces and soups. However, adding oil for sautéing or layering tomatoes into a dish with cheese or meat (like lasagna or pizza) can multiply the total calories fast, even if the tomatoes themselves are light.

Tomatoes and Glycemic Index

Tomatoes have a low glycemic index (GI) — around 15 — meaning they have minimal impact on blood sugar. Their fibre, water, and acidity slow digestion and glucose absorption. That makes tomatoes one of the safest fruits for people managing blood sugar, insulin resistance, or diabetes, especially when eaten raw or minimally processed.

Canned and Processed Tomatoes

Canned tomatoes, crushed tomatoes, and tomato paste have slightly more calories per gram due to reduced water content. A half-cup of canned tomatoes has about 40 calories, while tomato paste can contain 60–90 calories per quarter cup. Sugar and oil are often added to store-bought tomato sauces and ketchups, which can push a tablespoon of ketchup up to 15–20 calories, mostly from sugar. Always read the label to see what’s been added.

Tomatoes Feel “Free” — But Add Up in Sauces and Meals

Because tomatoes are so low in calories, many people treat them as calorie-free in cooking — and that’s mostly fine for raw use. But once tomatoes are cooked down into sauces, the calorie concentration increases significantly per spoonful. A full cup of tomato sauce made from fresh tomatoes might still be under 80 calories, but once it’s simmered with oil, garlic, or onions — or turned into marinara — it’s often 150+ calories per cup, even before cheese or pasta is added.

Juiced Tomatoes Are Less Satisfying

Tomato juice is often marketed as a healthy snack or low-calorie option. While an 8 oz glass contains only 40–50 calories, it lacks the fibre, chew, and bulk of a whole tomato — meaning it won’t keep you full the same way. It also tends to be high in sodium, especially in commercial brands, which can lead to bloating or mask your body’s natural fullness signals. Whole tomatoes always outperform juiced versions for satiety per calorie.

The Satiety Index Is Surprisingly High

A study that ranked foods by how full they make you feel per calorie found that tomatoes performed well — especially when paired with lean protein or whole grains. Their water content expands in the stomach, triggering stretch receptors, while the fibre slows digestion. This makes tomatoes a smart ingredient in weight-loss-friendly meals — they increase portion size and visual volume without adding significant calories.

Cherry Tomatoes Are Easy to Overeat — Still Safe

Cherry or grape tomatoes are often used as snacks or salad toppings — and at 3 to 5 calories each, they’re one of the rare foods that you can graze on freely without blowing your calorie goals. A whole cup of cherry tomatoes has fewer than 35 calories. That said, dipping them in ranch, oil, or hummus can quietly triple the calorie load, so portion control shifts from the tomato to the topping.

Tomatoes in Restaurant Meals Are Usually Calorie Carriers

In commercial meals — sandwiches, pasta, tacos — tomatoes are often not the problem, but they come with oil, cheese, mayo, or cream. People see “tomato” on the ingredient list and assume health, but the calorie payload often comes from the sauce or preparation method. A sun-dried tomato pesto, for example, can pack 100 calories per tablespoon, while tomato cream sauces in restaurants often exceed 400–500 calories per serving due to butter and cream.

Bottom Line

Tomatoes are one of the most forgiving foods for calorie-conscious eating. You can eat them raw, roast them, blend them, or toss them into almost any dish — and still stay well within your calorie goals. Just watch what’s added to them, especially in restaurant meals or jarred sauces. The tomato itself isn’t the trap — the company it keeps often is.

Tomatoes Are Nutrient-Dense, Not Energy-Dense

A key distinction: tomatoes aren’t just low in calories — they’re high in nutrient density. That means per calorie, they provide a high return on vitamins, antioxidants, and water. Lycopene, in particular, becomes more bioavailable when tomatoes are cooked — especially in the presence of a small amount of healthy fat like olive oil. This makes tomato-based dishes like homemade marinara, roasted tomato soup, or baked cherry tomatoes even more valuable nutritionally — if the fat is controlled.

Tomatoes Work as a Volume-Boosting Strategy

Because of their water and fibre content, tomatoes can be used to increase the physical size of meals without adding many calories. This is especially effective for those managing a calorie deficit or appetite. Chopped tomatoes added to omelettes, grain bowls, salads, wraps, or pasta increase satisfaction through visual fullness and chew time, which helps regulate portions naturally without needing hard calorie restriction.

Vine-Ripened vs Greenhouse Tomatoes: Same Calories, Different Taste

Calorie-wise, there's no major difference between vine-ripened, greenhouse, or hydroponic tomatoes — they all land in the 18–25 calorie range per 100 grams. The real variation is flavour and texture, not energy. However, sun-ripened or heirloom tomatoes may contain slightly more natural sugar due to ripeness, but this difference is minimal and doesn’t materially change calorie count unless you’re eating them by the pound.

Frozen, Diced, and Tinned Tomatoes Are Safe for Calorie Counting

Unlike many canned vegetables, most tinned or boxed tomatoes (diced, peeled, stewed) are very close in calorie count to raw versions — usually 25–35 calories per 100g, depending on concentration. The key is to avoid versions with added sugar, oils, or sauces — especially "Italian-style" or pre-seasoned blends, which can contain 60–100 calories per half-cup due to added ingredients.

Calorie-Safe

Tomatoes are one of the most calorie-safe, nutrient-rich, and diet-friendly foods you can eat. They're hydrating, satisfying, low-GI, and versatile. Calorie creep with tomatoes only happens when they’re part of dishes loaded with oil, cheese, or refined carbs. When kept clean and simple, they’re nearly impossible to overeat and can be used strategically to stretch meals, support fat loss, or replace higher-calorie condiments and sides.

Summary

A medium tomato contains just 22 calories, with high water content, fibre, and powerful antioxidants like lycopene. Tomatoes are incredibly low in energy but rich in nutrients, making them a go-to ingredient in low-calorie, weight-conscious diets. Whether eaten raw, roasted, or blended into sauces, they’re versatile, filling, and blood-sugar friendly. Just watch for added oils or sugars in processed tomato products.