How much protein is in raw tomatoes?

Raw tomatoes has 0.9 g of protein per 100 g and 1.6 g per 1 cup, chopped or sliced (180 g). That is 5 g of protein per 100 kcal — a modest protein contribution.

Where do these calorie figures come from?

USDA FoodData Central record 170457, “Tomatoes, red, ripe, raw, year round average” (SR Legacy, FDC SR Legacy 2018-04 + FNDDS 2024-10-31). Energy is USDA nutrient 1008 (Energy, kcal); protein, fat and carbohydrate are read from the same record. USDA data is in the public domain, and the FDC ID above links straight to it.

All foods

Everyday vegetablesUSDA SR LegacyFDC 170457

Calories in raw tomatoes

USDA FoodData Central record for “Tomatoes, red, ripe, raw, year round average” — per 100 g, per every USDA serving size, and next to the other everyday vegetables rows.

The short answer

Raw tomatoes: 18 kcal per 100 g. 1 cup, chopped or sliced (180 g) is 32 kcal with 1.6 g of protein. Source: USDA FoodData Central record 170457, "Tomatoes, red, ripe, raw, year round average".

Per 100 g

Nutrient	Per 100 g	Share of energy
Energy	18 kcal	100%
Protein	0.9 g	17%
Fat	0.2 g	9%
Carbohydrate	3.9 g	74%

Raw tomatoes is 18 kcal per 100 g in USDA FoodData Central (SR Legacy). Of that energy, about 17% comes from protein, 9% from fat and 74% from carbohydrate. That works out to 5 g of protein per 100 kcal — a modest protein contribution.

Per serving

The serving sizes USDA lists for this record, priced from the per-100 g figures above. Nothing here is rounded to a “portion” — the gram weight next to each label is what the calories are computed from.

Serving	Weight	Calories	Protein	Fat	Carbs
100 g	100 g	18	0.9 g	0.2 g	3.9 g
1 cup cherry tomatoes	149 g	27	1.3 g	0.3 g	5.8 g
1 cup, chopped or sliced	180 g	32	1.6 g	0.4 g	7 g
1 Italian tomato	62 g	11	0.6 g	0.1 g	2.4 g
1 cherry	17 g	3	0.2 g	0 g	0.7 g
1 large whole (3" dia)	182 g	33	1.6 g	0.4 g	7.1 g
1 medium whole (2-3/5" dia)	123 g	22	1.1 g	0.2 g	4.8 g
1 slice, medium (1/4" thick)	20 g	4	0.2 g	0 g	0.8 g
1 plum tomato	62 g	11	0.6 g	0.1 g	2.4 g

Compared with other everyday vegetables

Food	kcal / 100 g	Protein / 100 g	Per serving
Raw carrots	41	0.9 g	52 kcal · 1 cup chopped
Raw tomatoes	18	0.9 g	32 kcal · 1 cup, chopped or sliced
Raw cucumber	15	0.7 g	45 kcal · 1 cucumber (8-1/4")
Raw onions	40	1.1 g	64 kcal · 1 cup, chopped
Raw red bell pepper	26	1 g	39 kcal · 1 cup, chopped
Raw white mushrooms	22	3.1 g	15 kcal · 1 cup, pieces or slices
Sweet corn	86	3.3 g	123 kcal · 1 ear, large (7-3/4" to 9" long) yields
Green peas	81	5.4 g	117 kcal · 1 cup

Worth knowing

Tomatoes are 95% water and 18 kcal per 100 g. A medium tomato (~123 g) is about 22 kcal — one of the few foods where the cooking oil in a sauce outweighs the vegetable several times over.

Other tables in vegetables and vegetable products

The same numbers for the foods this one usually shares a plate — or a shopping list — with.

Questions about raw tomatoes

How many calories are in raw tomatoes?: Raw tomatoes: 18 kcal per 100 g. 1 cup, chopped or sliced (180 g) is 32 kcal with 1.6 g of protein. Source: USDA FoodData Central record 170457, "Tomatoes, red, ripe, raw, year round average".
How much protein is in raw tomatoes?: Raw tomatoes has 0.9 g of protein per 100 g and 1.6 g per 1 cup, chopped or sliced (180 g). That is 5 g of protein per 100 kcal — a modest protein contribution.
Where do these calorie figures come from?: USDA FoodData Central record 170457, “Tomatoes, red, ripe, raw, year round average” (SR Legacy, FDC SR Legacy 2018-04 + FNDDS 2024-10-31). Energy is USDA nutrient 1008 (Energy, kcal); protein, fat and carbohydrate are read from the same record. USDA data is in the public domain, and the FDC ID above links straight to it.

How calorie.one logs it

Type “raw tomatoes” into calorie.one and the app matches this exact record — “Tomatoes, red, ripe, raw, year round average” — estimates the grams, and shows the line with its USDA label. You correct the amount; the per-100 g figure is never guessed. That split between recognition and arithmetic is the whole methodology. For the numbers in context, read How to track mixed meals accurately with AI.