How many carbs are in a tomato?
A medium tomato (123g) has about 4.8g of carbohydrate and 3.3g of net carbs. That is one of the lowest carb counts of any common produce item.
Carbs by portion
| Portion | Total carbs | Fiber | Net carbs |
|---|---|---|---|
| 1 medium tomato (123g) | 4.8g | 1.5g | 3.3g |
| 1 small whole (91g) | 3.5g | 1.1g | 2.4g |
| 1 large whole (182g) | 7.1g | 2.2g | 4.9g |
| 1 cup cherry tomatoes (149g) | 5.8g | 1.8g | 4.0g |
| 100 grams | 3.9g | 1.2g | 2.7g |
Net carbs
A medium tomato has about 3.3g of net carbs, which is total carbs (4.8g) minus fiber (1.5g). That is low enough that many people on low-carb diets eat tomatoes freely. See the net carbs guide for when to use net instead of total.
Glycemic index of a tomato
The glycemic index of a tomato is about 15. Tomatoes have a very low glycemic index and a negligible glycemic load at any normal portion. The low carb density means a medium tomato adds only about 0.7g of glucose load.
For diabetes
A medium tomato has about 4.8g of carbs, which is small enough that most care teams do not count it toward a meal bolus unless portions are large. A full cup of chopped tomato is about 7g of carbs, still modest. Tomatoes do not spike blood glucose in standard servings. Tomato sauce, juice, and ketchup are different because they concentrate carbs and sugar significantly. See the diabetes carb-counting guide for how to handle processed tomato products.
Keto and low carb
One medium tomato has about 3.3g of net carbs, which fits easily within a 20 to 30g daily keto budget. Cherry tomatoes in a salad add less than 1g of net carbs per fruit. Tomatoes are one of the few fruits that most keto plans allow freely, as long as you are eating them whole rather than as paste or sauce.
Good to know
Tomato products vary wildly in carb concentration. A tablespoon of tomato paste has about 4g of carbs, roughly the same as a whole medium raw tomato. A half-cup of canned crushed tomatoes runs about 9g. Ketchup adds about 4g per tablespoon from added sugar. If you are counting carbs carefully, the form matters more than the raw tomato itself.
Full nutrition (per 100g)
- Calories: 18.0 kcal
- Carbohydrate: 3.89g
- Fiber: 1.2g
- Sugars: 2.63g
- Protein: 0.88g
- Fat: 0.2g
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Get the appFrequently asked questions
How many carbs are in a tomato?
A medium tomato (123g) has about 4.8g of carbohydrate. A large tomato (182g) has about 7.1g and a cherry tomato has under 1g.
How many net carbs are in a tomato?
A medium tomato has about 3.3g of net carbs, which is total carbs (4.8g) minus fiber (1.5g).
Is a tomato a fruit or vegetable for carb counting?
Botanically a fruit, but for carb counting it behaves like a low-carb vegetable. A medium tomato has only 4.8g of carbs compared to 29g in a medium banana.
Are tomatoes keto?
Yes, whole raw tomatoes fit keto. A medium tomato has about 3.3g of net carbs. Tomato paste and ketchup are much higher in carbs and need to be counted carefully.
How many carbs are in a cup of cherry tomatoes?
A cup of cherry tomatoes (149g) has about 5.8g of total carbs and 4g of net carbs.