One medium plum tomato has about 3 grams of carbs, with about 1 gram of fiber and under 2 grams of sugar.
Roma tomatoes stay on the low end for carbs, which is why they fit so easily into salads, omelets, wraps, and sauce-based meals. They’re fleshier than many round tomatoes, with less juice and fewer seeds, so the bite feels dense even though the carb load stays modest.
If you want one clean number, use this: a medium Roma tomato lands at about 2.5 to 3 grams of total carbs. That’s a small amount for a whole tomato, not a sliced serving.
Why Roma Tomatoes Tend To Stay Lower In Carbs
Roma tomatoes are a plum type. They’re known for thicker walls and less watery flesh than slicing tomatoes, which is part of why they’re used so often in sauces and roasting. The shape also makes portioning easy. One tomato, two tomatoes, half a cup sliced — the count is simple to track.
Carb counts for produce change with size. That’s the part that trips people up. A tiny Roma from a salad bar and a fat one from the market are both “one tomato,” yet their weights can be far apart. So the best way to read the number is by weight first, then by the tomato count you actually eat.
What The Base Number Looks Like
USDA tomato data puts raw ripe tomatoes at about 3.9 grams of carbohydrate per 100 grams. Fiber makes up about 1.2 grams of that amount. So the net carb figure ends up close to 2.7 grams per 100 grams. For a food that adds volume, color, and moisture to a meal, that’s a light carb trade.
That base figure also tells you why Roma tomatoes feel easy to fit into lower-carb meals. Even if you eat two medium ones, you’re still only around 5 to 6 grams of total carbs.
How Many Carbs Are In Roma Tomato? By Size And Portion
The cleanest way to estimate carbs in a Roma tomato is to think in grams. A plum tomato around 60 to 65 grams comes out close to 2.4 to 2.5 grams of total carbs. A larger one near 80 grams pushes closer to 3 grams.
That means the answer most readers want is simple: one medium Roma tomato usually has about 2.5 to 3 grams of carbs. If you dice a few into a sauce or salad, the count climbs slowly, not sharply.
Serving Size Matters More Than Variety Names
Labels like Roma, plum, Italian plum, or paste tomato tell you the style of tomato, not the exact carb count of one piece. Grocery store size still matters most. Two small Roma tomatoes can match one large tomato in weight, so the carbs end up almost the same.
If you track carbs closely, weigh them once or twice at home. After that, you’ll get a good eye for it.
According to USDA FoodData Central tomato data, raw tomatoes stay low in total carbohydrate per 100 grams, which makes weight-based tracking a better method than guessing by shape.
Carb Estimates For Common Roma Tomato Portions
The table below gives practical carb estimates for the serving sizes people use most. These figures use the standard raw tomato carb value and round to an easy kitchen number.
| Portion | Total Carbs | Fiber / Net Carbs |
|---|---|---|
| 1 small Roma tomato (40 g) | About 1.6 g | 0.5 g fiber / 1.1 g net |
| 1 medium-small Roma tomato (50 g) | About 1.9 g | 0.6 g fiber / 1.3 g net |
| 1 medium Roma tomato (62 g) | About 2.4 g | 0.7 g fiber / 1.7 g net |
| 1 large Roma tomato (80 g) | About 3.1 g | 1.0 g fiber / 2.1 g net |
| 2 medium Roma tomatoes (124 g) | About 4.8 g | 1.5 g fiber / 3.3 g net |
| 3 medium Roma tomatoes (186 g) | About 7.2 g | 2.2 g fiber / 5.0 g net |
| 1/2 cup chopped Roma tomato (85 g) | About 3.3 g | 1.0 g fiber / 2.3 g net |
| 1 cup chopped tomato (170 g) | About 6.6 g | 2.0 g fiber / 4.6 g net |
Those numbers show why Roma tomatoes rarely make or break a meal plan on their own. The bigger carb swing usually comes from what you pair them with: pasta, bread, sweet dressings, ketchup, or store-bought sauces.
What Those Carbs Are Made Of
Most of the carbs in a Roma tomato come from natural sugars, with a smaller share from fiber. That mix is one reason tomatoes taste mildly sweet without acting like a sugary food.
On a Nutrition Facts panel, total carbohydrate includes fiber and sugars. The FDA’s Daily Value page for total carbohydrate and fiber is handy if you want to place a serving in the wider day’s intake instead of staring at the gram count alone.
Fresh Tomato Versus Tomato Products
This is where the count can change fast. Fresh Roma tomatoes carry a lot of water. Once you cook them down into paste or a thick sauce, the water drops and the carbs per spoonful rise. That does not make tomato paste “bad.” It just means the food is more packed.
A sliced raw Roma tomato on a sandwich adds little. A few spoonfuls of concentrated paste in a recipe add more. Same food family, different density.
Where Roma Tomatoes Fit In Lower-Carb Eating
Roma tomatoes work well when you want flavor without much carb load. They add acid, sweetness, and texture to meals that can feel flat without them. Eggs, tuna, grilled chicken, cottage cheese, and leafy greens all pair well with them.
If you follow a lower-carb plan, you usually do not need to trim fresh Roma tomatoes from your plate. The sharper move is to watch the full dish. A tomato salad with olive oil and herbs is one thing. The same tomatoes baked into a sweet bottled sauce are another.
USDA’s Agricultural Research Service also notes that Roma tomatoes are a plum type bred with thick, fleshy walls, which helps explain why they’re used so often in sauce and cooked dishes. You can see that in USDA’s note on the Roma tomato.
Best Ways To Count Roma Tomato Carbs Without Overthinking It
You do not need a food scale every time. Use one of these simple habits instead:
- Count one medium Roma tomato as about 3 grams of carbs.
- Count a half cup chopped as about 3 grams.
- Count a full cup chopped as about 6 to 7 grams.
- Add extra attention only when the tomatoes are cooked down into paste, puree, or thick sauce.
That rough method is close enough for most home meals. Then, if you’re building a tighter plan, weigh the portion and use the 3.9 grams per 100 grams rule.
Quick Portion Guide For Real Meals
Most people do not eat Roma tomatoes in isolation. They eat them in bowls, salads, skillets, and sandwiches. This table makes those meal-size portions easier to judge at a glance.
| Meal Use | Roma Tomato Amount | Estimated Carbs |
|---|---|---|
| Omelet or scramble | 1/2 medium tomato | About 1 to 1.5 g |
| Side salad | 1 medium tomato | About 2.5 to 3 g |
| Sandwich or wrap filling | 2 to 3 slices | Under 1 g |
| Salsa bowl | 2 medium tomatoes | About 5 g |
| Roasted tray of vegetables | 3 medium tomatoes | About 7 g |
| Chopped topping for one lunch bowl | 1/2 cup | About 3.3 g |
The Takeaway On Roma Tomato Carbs
If you want the plain answer, one medium Roma tomato has about 3 grams of carbs. Smaller ones land closer to 2 grams. Larger ones land closer to 3 grams. That keeps fresh Roma tomatoes in the low-carb camp for most eating styles.
The number only starts to climb when the tomatoes pile up by the cup or get cooked down into concentrated products. So if you are counting carbs, fresh Roma tomatoes are rarely the thing to fear. The bread, pasta, or sweet sauce next to them usually matters more.
References & Sources
- USDA FoodData Central.“Food Search: Tomatoes.”Provides the raw tomato nutrient data used for the per-100-gram carbohydrate estimates in this article.
- U.S. Food and Drug Administration.“Daily Value on the Nutrition and Supplement Facts Labels.”Shows how total carbohydrate and dietary fiber are listed and interpreted on Nutrition Facts labels.
- USDA Agricultural Research Service.“ARS in Your Pizza.”States that Roma tomatoes are a plum type and describes their thick, fleshy structure and common sauce use.