Does Tomato Sauce Have Carbs? A Complete Guide to Counting

October 26, 2025 •

4 min read

According to the USDA, a single cup of canned tomato sauce typically contains around 13-16 grams of total carbohydrates. This means that yes, tomato sauce does have carbs, and the exact amount can vary significantly depending on the ingredients, especially added sugars, which can have a major impact.

Quick Summary

Tomato sauce does contain carbohydrates, with amounts varying by product and preparation. Added sugars in store-bought versions often increase the carb count, while homemade sauces offer better control over ingredients. Serving size is also critical for managing carbohydrate intake, particularly for low-carb diets.

Key Points

Source of Carbs: Tomatoes contain natural sugars, so all tomato sauces have some carbohydrates.
Hidden Sugars: Many store-bought sauces add sugar to balance acidity, which significantly increases the total carb count.
Homemade vs. Store-Bought: Homemade sauce gives you full control over ingredients and carb content, allowing for a healthier, low-carb option.
Net vs. Total Carbs: Net carbs are what matter most for low-carb diets, calculated by subtracting fiber from total carbs.
Keto-Friendly Options: Specific brands like Rao's and Primal Kitchen offer low-carb, keto-friendly sauces without added sugar.
Portion Control is Key: A small serving of sauce is generally acceptable on a low-carb diet, but large portions can add up quickly.
Flavor Alternatives: Use herbs, spices, and healthy fats instead of sugar to enhance flavor and reduce acidity in homemade sauce.

Understanding Carbohydrates in Tomato Sauce

Tomato sauce, a staple in many cuisines, gets its carbs primarily from the natural sugars found in tomatoes. While raw tomatoes are relatively low in carbohydrates, the process of concentrating them into a sauce, especially when using tomato paste, increases the density of nutrients—including carbs. The crucial difference in carbohydrate content comes down to whether the sauce is homemade or store-bought, and whether it contains added sugars.

The Breakdown of Carbs in Sauce

For those managing their carbohydrate intake, it's important to distinguish between total carbs and net carbs. Net carbs are calculated by subtracting fiber from total carbohydrates, and they represent the carbohydrates that your body can actually digest and convert into glucose. Tomatoes are a source of dietary fiber, which helps offset some of their total carb content. For example, one cup of canned tomato sauce with no salt added contains approximately 13 grams of total carbohydrates but only 9.3 grams of net carbs due to its fiber content.

Homemade vs. Store-Bought: The Sugar Factor

Most store-bought tomato sauces often contain hidden sugars to balance the natural acidity of the tomatoes and enhance flavor. This can significantly increase the total and net carb counts compared to a homemade sauce. Brands like Prego and Bertolli, for instance, have been noted to contain higher levels of added sugar than some organic or keto-friendly alternatives. Making sauce from scratch allows you to use fresh or canned tomatoes without added sugar, controlling the final carb count precisely.

List of ingredients that increase carb count in sauce:

Added sugar (e.g., cane sugar, corn syrup)
High-carb vegetables used as fillers, like extra onions
Processed thickeners and starches

List of low-carb, flavor-boosting alternatives:

Herbs (fresh basil, oregano, thyme)
Spices (garlic powder, black pepper, red pepper flakes)
High-quality fats (olive oil, avocado oil, butter)

Low-Carb and Keto Diet Considerations

For individuals on very low-carb diets like the ketogenic diet, portion control is paramount. While a quarter-cup serving of low-sugar tomato sauce can fit within a daily carb limit, a full cup may take up a significant portion of a day's allowance. Certain store-bought brands, such as Rao's Homemade and Primal Kitchen, specifically market their products as keto-friendly with minimal net carbs.

Comparison of Homemade vs. Store-Bought Sauce


Feature	Homemade Tomato Sauce	Store-Bought Tomato Sauce
Carbohydrate Control	High—You control all ingredients.	Varies greatly; can be high due to added sugars.
Added Sugar	None, unless you add a low-carb sweetener.	Often contains added sugars to balance acidity.
Ingredients	Fresh tomatoes, herbs, olive oil, optional low-carb spices.	Tomatoes, sugar, starches, natural flavors, and preservatives.
Net Carbs (per 1/4 cup)	Generally lower, depending on the recipe.	Can range significantly; Rao's is ~2.5g.
Preparation	Requires more time and effort.	Convenient, ready-to-use product.
Flavor	Customizable, fresh, and often more robust.	Can be less complex due to processing.

Making Your Own Low-Carb Tomato Sauce

Creating a delicious, low-carb tomato sauce at home is a straightforward process. By focusing on high-quality ingredients, you can control flavor and nutrition. Using crushed or diced tomatoes with no salt added as a base is a great starting point. Sautéing aromatics like garlic and onions in olive oil builds a deep flavor foundation. A touch of low-carb sweetener, such as erythritol or monk fruit, can be added to counteract acidity without raising the carb count. Alternatively, a knob of butter swirled in at the end can also cut the acid and add richness. For a richer, more concentrated flavor, using a small amount of tomato paste can work, but remember that it is also higher in carbs per serving.

Conclusion

In summary, tomato sauce does contain carbohydrates, but the total amount and its effect on your diet largely depend on the product's preparation and your serving size. While commercially prepared sauces often contain added sugars that increase the carb content, low-carb or keto-friendly options are available. The most reliable way to manage carb intake from tomato sauce is to make it at home, giving you full control over the ingredients. For those on low-carb diets, paying attention to labels and practicing portion control are the best strategies for incorporating this versatile and flavorful sauce into their meals without derailing their goals.

Understanding the Labels: A Final Look

When purchasing pre-made sauce, always check the nutritional label and ingredient list carefully. The order of ingredients indicates their proportion, so if sugar or corn syrup is near the top, it's a high-sugar product. Comparing brands for net carbs and focusing on 'no sugar added' varieties is key. Ultimately, a little knowledge goes a long way in enjoying tomato sauce as part of a healthy, balanced diet.

Key considerations for low-carb diets:

Opt for homemade or 'no sugar added' varieties.
Pay close attention to serving sizes.
Read the ingredient list to spot hidden sugars.

For those who need to limit carbs for health reasons, such as managing blood sugar, selecting a sauce with a low glycemic index and glycemic load is beneficial. Making the right choice ensures you can still enjoy the robust flavor of tomato sauce while maintaining your dietary goals.

Final Takeaway: By checking labels for added sugars and controlling portion sizes, you can easily include tomato sauce in a low-carb diet. Choosing a homemade or specialized low-carb brand offers the most control over carbohydrate content.

Frequently Asked Questions

To check for added sugar, read the ingredient list on the nutritional label. If you see cane sugar, high-fructose corn syrup, or other sweeteners listed near the top, the sauce likely has a high sugar content. Look for 'no sugar added' on the label.

No, the carb content varies. A fresh tomato is lower in carbs than tomato paste, which is a concentrated product. The same applies to sauce, where the level of processing and added ingredients can dramatically change the nutritional profile.

Total carbs are the total amount of carbohydrates in a serving. Net carbs are the total carbohydrates minus the dietary fiber. Because fiber is not digested, net carbs have a lesser impact on blood sugar, and this is what low-carb dieters typically count.

Yes, but you must be mindful of portion sizes and added sugars. It is recommended to choose a keto-friendly brand like Rao's or make your own from scratch to ensure a low net carb count.

To reduce carbs, use crushed tomatoes without added sugar, add low-carb vegetables like bell peppers, and avoid using excess tomato paste. You can use a low-carb sweetener or a small amount of butter to cut acidity.

Manufacturers add sugar to balance the acidity of the tomatoes and create a more appealing, sweeter flavor profile. This is especially common in less expensive or mass-produced brands.

For a low-carb meal, you can serve a low-carb tomato sauce over zucchini noodles (zoodles), shirataki noodles, or spaghetti squash instead of traditional pasta.