Calories in Tomatoes

Q: How much sugar do tomatoes have?

1 slice of tomatoes (20 g) has 0.53 g of sugar, and 100 g has 2.6 g.

Q: How many calories in each size of tomatoes?

It depends on the size: slice (20 g) about 4 kcal; small (91 g) about 18 kcal; medium (123 g) about 25 kcal; large (182 g) about 36 kcal.

Q: Are tomatoes low carb or keto-friendly?

Yes. 100 g of tomatoes has only 2.8 g of net carbs (carbs minus fiber), little enough for most low-carb and keto diets.

Q: Do tomatoes contain lycopene?

Yes. 100 g of tomatoes has 2813 µg of lycopene.

Q: Are tomatoes low in calories?

Yes. 100 g of tomatoes has only 20 kcal.

Q: Will eating tomatoes help me lose weight?

It can be part of a diet that loses weight: what counts is the total calories you eat in a day, not any single food. 1 slice of tomatoes (20 g) has about 4 kcal. The calorie calculator works out how many you need.

100 g of tomatoes has 20 kcal, and 1 slice of tomatoes (20 g) has about 4 kcal.

20 kcalper 100 g

4 kcal in 1 slice (20 g)

Very low density · 0.2 kcal per g

Protein 0.8g 15% of the calories
Carbs 4g 73% of the calories
Fat 0.3g 13% of the calories
Fiber 1.2g

Per 100 g. Figures from USDA FoodData Central. Averages across measured samples; a few percent either way is normal. Updated 2026-10-04.

100 g is about 5 minutes of walking, or 2 minutes of running, for a 70 kg body - context, not a debt to work off.

Tomatoes nutrition facts

A dash means nobody measured it - not that there is none of it.

Per serving: 1 slice (20 g)
Nutrient	Per 100 g	Per serving
Energy	20kcal	4kcal
Fat	0.31g	0.062g
Saturated Fat	0.03g	0.006g
Unsaturated Fat	0.28g	0.056g
Carbs	4g	0.81g
Sugars	2.6g	0.53g
Fiber	1.2g	0.24g
Protein	0.82g	0.16g
Salt	0.01g	0.002g
Water	94.4g	18.9g

Alcohol	0g	0g
Caffeine	0mg	0mg

Monounsaturated	0.031g	0.006g
Polyunsaturated	0.083g	0.017g
Omega-3	0.003g	0.001g
ALA	0.003g	0.001g
DHA	0g	0g
EPA	0g	0g
Omega-6	0.08g	0.016g
AA	0g	0g
LA	0.08g	0.016g
Cholesterol	0mg	0mg

Vitamin B1 (Thiamine)	0.046mg	0.009mg
Vitamin B2 (Riboflavin)	0.018mg	0.004mg
Vitamin B3 (Niacin)	0.6mg	0.12mg
Vitamin B6 (Pyridoxine)	0.078mg	0.016mg
Vitamin B12 (Cobalamin)	0µg	0µg
Folate (Vitamin B9)	13µg	2.6µg
Vitamin A	32µg	6.4µg
Vitamin C	16.3mg	3.3mg
Vitamin D	0IU	0IU
Vitamin E	0.58mg	0.12mg
Vitamin K	7.5µg	1.5µg
Choline	7mg	1.4mg

Calcium	10mg	2mg
Copper	0.051mg	0.01mg
Iron	0.22mg	0.044mg
Magnesium	10mg	2mg
Phosphorus	23mg	4.6mg
Potassium	226mg	45.2mg
Selenium	0µg	0µg
Zinc	0.15mg	0.03mg

Beta-carotene	397µg	79.4µg
Lycopene	2813µg	563µg
Lutein + zeaxanthin	103µg	20.6µg
Flavonoids	1.5mg	0.3mg
Flavanones	0.68mg	0.14mg
Flavonols	0.8mg	0.16mg

Cystine	0.008g	0.002g
Histidine	0.013g	0.003g
Isoleucine	0.017g	0.003g
Leucine	0.023g	0.005g
Lysine	0.025g	0.005g
Methionine	0.006g	0.001g
Phenylalanine	0.025g	0.005g
Threonine	0.025g	0.005g
Tryptophan	0.006g	0.001g
Tyrosine	0.013g	0.003g
Valine	0.017g	0.003g

Read it as an averageIt is what a laboratory measured, averaged over samples - variety, ripeness and cut all move it, and a few percent either way is normal.

What stands out in tomatoes

1 slice (20 g) is 4 kcal, about <1% of a 2,000 kcal day.

Low in calories20 kcal per 100 g
Low in fat0.31 g per 100 g
Low in saturated fat0.03 g per 100 g
Low in sugars2.6 g per 100 g
Low in salt0.01 g per 100 g

Claims follow the EU nutrition claims rules and the "high" warnings the UK/EU front-of-pack labels; the 2,000 kcal day is the reference intake for an average adult.

Calories in different amounts of tomatoes

20 g1 slice	4 kcal
40 g2 servings	8 kcal
50 g	10 kcal
100 g	20 kcal
200 g	40 kcal

Any amount g 4 kcal

Foods with similar calories

Other published foods within reach of 20 kcal per 100 g, so the number has something to sit against.

Broccoli 11 kcal more 31kcal / 100 g

Spinach 7 kcal more 27kcal / 100 g

Lettuce Same calories 20kcal / 100 g

Onion 18 kcal more 38kcal / 100 g

Asparagus Same calories 20kcal / 100 g

Green beans 11 kcal more 31kcal / 100 g

Questions about tomatoes

1 slice of tomatoes (20 g) has 0.53 g of sugar, and 100 g has 2.6 g.

It depends on the size: slice (20 g) about 4 kcal; small (91 g) about 18 kcal; medium (123 g) about 25 kcal; large (182 g) about 36 kcal.

Yes. 100 g of tomatoes has only 2.8 g of net carbs (carbs minus fiber), little enough for most low-carb and keto diets.

Yes. 100 g of tomatoes has 2813 µg of lycopene.

Yes. 100 g of tomatoes has only 20 kcal.

It can be part of a diet that loses weight: what counts is the total calories you eat in a day, not any single food. 1 slice of tomatoes (20 g) has about 4 kcal. The calorie calculator works out how many you need.

Track anywhere. On any device.

Your calorie counter and food diary in your pocket, free and without ads, with Tide one tap away.

Log by photo, barcode or voice, right where you eat
Steps and workouts from Apple Health and Health Connect
The same log on your phone and in your browser, always in sync

GET IT ON Google Play