Tomatoes contain about 3 grams of net carbs per 100 grams (about 5 grams per cup). But if you’re eating a strict keto low-carb diet (below 20 grams per day) it’s worth keeping in mind that the carbs do add up, and you can only eat a moderate amount of tomatoes to stay under that limit.Click to see full answer. Likewise, people ask, how many carbs are in one tomato? Tomatoes One cup (149 grams) of cherry tomatoes contains 6 grams of carbs, 2 of which are fiber (55). Tomatoes are a good source of vitamins A, C and K.Beside above, how many carbs are in a large tomato? Your standard tomatoes have four grams of carbs and two grams of sugar per half cup serving, according to the United States Department of Agriculture (USDA). However, the counts vary a little depending on the type of tomato you go for. Herein, can you eat tomatoes on keto diet? While tomatoes are technically a fruit, you can have them on a keto diet, but again be careful as their carbs are a bit higher and, combined with other foods, may take you up over 20 grams net carbs a day if you consume too much.What are the nutrition facts of a tomato? One cup of chopped or sliced raw tomatoes contains: 32 calories (kcal) 170.14 g of water. 1.58 g of protein. Tomatoes also have a wealth of vitamin and mineral content, including: 18 mg of calcium. 427 mg of potassium. 43 mg of phosphorus. 24.7 mg of vitamin C. 1499 international units (IU) of vitamin A.