How many carbs are in a Tomato?
A 1 medium (123g) serving of Tomato contains 4.8g of total carbs (3.3g net carbs), 3.2g sugar, 22 calories, 1.1g protein, 0.2g fat and 1.5g fiber.
- Calories
- 22 cal
- Carbohydrates
- 4.8 g
- of which Sugars
- 3.2 g
- Fiber
- 1.5 g
- Net carbs
- 3.3 g
- Protein
- 1.1 g
- Fat
- 0.2 g
Tomato nutrition at a glance
Per 1 medium (123g), Tomato delivers about 1% of a 2,000-calorie daily reference, 2% of the 275g daily carbohydrate reference and 5% of the 28g daily fiber reference. Sugar sits at 6% of the 50g added-sugar reference and protein contributes 2% of the 50g protein reference.
- Calories
- 18
- Carbs
- 3.9 g
- Sugar
- 2.6 g
- Protein
- 0.9 g
- Fat
- 0.2 g
- Fiber
- 1.2 g
Blood-sugar impact of Tomato
Very little impact on blood sugar. Suitable for low-carb, keto and diabetic meal plans in normal serving sizes.
With 4.8g total carbs and 1.5g fiber, the net-carb figure for a 1 medium (123g) serving works out to roughly 3.3g — this is the number most keto and low-carb tracking apps use. If you're managing type 2 diabetes, pre-diabetes or reactive hypoglycemia, use total carbs for insulin dosing calculations and treat net carbs as a rough guide for meal planning.
Ways to eat Tomato
- Great fit for low-carb, keto or diabetic-friendly meals — build around tomato without worrying about a big glucose spike.
- Use tomato as a satisfying snack between meals when you want to stay in a low-carb window.
- Combine tomato with leafy greens and olive oil for a clean, blood-sugar-friendly plate.
Frequently asked questions
Is Tomato keto-friendly?
Yes. With only 3.3g net carbs per 1 medium (123g), Tomato fits comfortably inside a standard 20–50g/day keto carb budget.
How many carbs in Tomato per 100 grams?
About 3.9g of carbs, 2.6g sugar and 18 calories per 100g of Tomato.
How does Tomato affect blood sugar?
Very little impact on blood sugar. Suitable for low-carb, keto and diabetic meal plans in normal serving sizes.
Is Tomato good for weight loss?
A serving delivers 22 calories with 1.1g protein and 1.5g fiber. Foods that are relatively high in protein and fiber per calorie tend to be more filling — with a 12% combined protein-plus-fiber-to-calorie ratio, Tomato is a solid pick for a satiating, weight-loss-friendly meal.
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Open scannerSources & how these numbers are calculated
Nutrition values are consensus averages compiled from the USDA FoodData Central database for a typical 1 medium (123g) serving of Tomato. Actual values vary with brand, variety, ripeness and preparation — always check the label on packaged products. Daily-value percentages reference the U.S. FDA 2,000-calorie adult reference (275g carbs, 50g added sugar, 50g protein, 78g fat, 28g fiber).
Content reviewed by Carb Lens editorial. Read our editorial policy for how we source, review and update food data.