Calories in Watermelon: Per Cup, Slice and 100 g

Nothing says summer like a cold slice of watermelon. It’s sweet and juicy – so if you’re counting calories, you might wonder whether it’s as light as it tastes, or whether all that sweetness means lots of sugar.

The short answer: watermelon has only about 30 calories per 100 g. A cup of diced watermelon has about 46 calories, and a typical wedge about 86. It’s over 90% water, has less sugar than most fruits and is one of the best foods for eating a big portion with very few calories.

Calories in watermelon by portion

Values are for raw watermelon without the rind, from the US Department of Agriculture (USDA FoodData Central):

Portion	Weight	Calories
10 watermelon balls	122 g	37 kcal
1 cup, diced	152 g	46 kcal
1 small slice	about 150 g	about 45 kcal
1 wedge (1/16 of a large melon)	286 g	86 kcal
100 g	100 g	30 kcal
1 pound	454 g	136 kcal
1 whole large melon (15 in long)	4,518 g	1,355 kcal

Tip: the rind is roughly a third of a watermelon’s weight. If you weigh a slice with the rind, the part you eat is about two thirds of that.

Watermelon nutrition facts

Nutrient	Per 100 g	Per cup (152 g)
Calories	30 kcal	46 kcal
Carbohydrates	7.6 g	11.5 g
– of which sugars	6.2 g	9.4 g
Fiber	0.4 g	0.6 g
Protein	0.6 g	0.9 g
Fat	0.2 g	0.2 g
Water	91 g	139 g
Potassium	112 mg	170 mg
Vitamin C	8.1 mg	12 mg
Lycopene	4.5 mg	6.9 mg

Watermelon is 91% water, which is why it has so few calories. It’s also one of the best sources of lycopene – the red pigment also found in tomatoes – with more per 100 g than raw tomatoes. It has very little fiber or protein, though.

Calories in watermelon drinks, salads and snacks

Food	Portion	Calories
Watermelon juice (blended, no sugar)	1 cup (8 fl oz)	about 70 kcal
Watermelon and feta salad (2 cups melon, 1 oz feta, mint)	1 bowl	about 165 kcal
Same salad + 1 tbsp olive oil	1 bowl	about 285 kcal
Frozen watermelon “sorbet” (just blended melon)	1 cup	about 50 kcal
Watermelon seeds, roasted	1 oz (28 g)	about 160 kcal

Watermelon and feta salad is a great summer lunch, but the olive oil and cheese add more calories than the melon. Roasted watermelon seeds are a different story from the fruit: they’re like nuts, with about 560 calories per 100 g.

Is watermelon good for weight loss?

Yes. Watermelon is one of the most “volume-friendly” foods there is: a big bowl of 300 g has only about 90 calories. Foods with lots of water fill your stomach for few calories, which can help you eat less overall.

Two things to keep in mind:

• It isn’t very filling for long. It has almost no protein or fiber, so you may feel hungry again soon. As a snack, pair it with Greek yogurt, cottage cheese or a handful of nuts.
• Watermelon juice and smoothies fill you up less than the fruit you chew.

Remember that you lose weight only when you eat fewer calories than you burn. Read more about the calorie deficit and find your number with our calorie calculator. For more ideas, see our list of low calorie foods.

Watermelon and blood sugar

Watermelon has a high glycemic index (about 72–80), which sounds bad. But the glycemic index is measured with a portion that has 50 g of carbs – that’s about 700 g of watermelon. A normal cup has only about 11 g of carbs, so its glycemic load is low (about 8; anything up to 10 counts as low).

In other words: a cup or two of watermelon won’t spike your blood sugar much for most people. If you have diabetes, eat it in normal portions, ideally after a meal or with some protein, and ask your doctor or dietitian what fits your plan. Read more about low glycemic fruits.

How to eat watermelon when you’re losing weight

1. Use it as dessert in summer instead of ice cream or cake.
2. Freeze cubes and blend them into a no-sugar “sorbet”.
3. Make a salad with cucumber, mint and a little feta – and measure the oil.
4. Pair it with protein if you eat it as a snack.
5. Choose the fruit over the juice.

Count the calories in your watermelon without guesswork. With NutriSmart, you snap a photo of what you eat, and the app counts your calories, protein, carbs and fat and shows how much you have left for the day. In the food library, you can also see the glycemic index of each food.Get the app free

You can also read how many calories are in strawberries, an apple and cucumber.

The bottom line

Watermelon has about 30 calories per 100 g, 46 per cup and about 86 per typical wedge. It’s over 90% water, has less sugar than most fruits and a low glycemic load in normal portions. It’s a great choice for weight loss – just remember it isn’t very filling on its own, so pair it with some protein.