How many calories are in watermelon?
A 1 cup, diced (152 g) has 46 calories. Per 100 grams, watermelon has 30 calories. Watermelon is about 92% water by weight, so its calorie density is among the lowest of any fruit. That cup has about 11 g of carbohydrate, most of it sugar, with minimal fiber, protein, or fat.
Watermelon nutrition facts
| Nutrient | Per 1 cup, diced (152 g) | Per 100 g |
|---|---|---|
| Calories | 46 | 30 |
| Protein | 0.9 g | 0.6 g |
| Carbohydrate | 11.5 g | 7.6 g |
| Fiber | 0.6 g | 0.4 g |
| Sugar | 9.4 g | 6.2 g |
| Fat | 0.2 g | 0.2 g |
| Vitamin C | 12 mg | 8 mg |
| Potassium | 170 mg | 112 mg |
Values from Watermelon, raw (USDA FoodData Central, FDC ID 167765). Figures vary with variety, ripeness, and preparation.
The calories you might not be counting
Watermelon is so low in calories per bite that the fruit itself is almost never the problem. What catches people is volume. A standard wedge (1/16 of a melon) is 286 g and about 86 calories, and at a barbecue or pool party it is easy to eat two or three wedges without noticing. Three wedges total roughly 260 calories, which is still modest, but it is five times what a person tracking "a slice of watermelon" tends to log. The other trap is watermelon juice: blended with added sugar or mixed into a cocktail, the sugar doubles and the volume control disappears. Forkd asks for the portion and catches the gap between a cup and a quarter of a melon.
Calories by size
A cup of diced watermelon (152 g) is the standard reference, but most people eat wedges. USDA lists a wedge as 1/16 of a melon at 286 g (about 86 calories). A whole melon is 4,518 g and around 1,355 calories. The difference between a cup and a wedge is nearly double, which is why portion clarity matters even for a low-calorie fruit.
| Size | Weight | Calories |
|---|---|---|
| 1 cup, diced | 152 g | 46 |
| 1 cup, balls | 154 g | 46 |
| Wedge (1/16 of melon) | 286 g | 86 |
| 10 watermelon balls | 122 g | 37 |
Scanning watermelon with Forkd catches the exact portion and the hidden extras this page just described, the oil, the dressing, the topping a photo alone would miss.
Watermelon calories: common questions
Is watermelon good for weight loss?
At 30 calories per 100 g and 92% water, watermelon is one of the most filling low-calorie foods available. It fits weight loss well as long as portions are tracked, since the ease of eating large volumes can add up.
How many calories are in a slice of watermelon?
A standard wedge (1/16 of a melon, 286 g) has about 86 calories. A cup of diced watermelon (152 g) is about 46 calories. Per 100 g, watermelon is 30 calories.
Is watermelon high in sugar?
A cup of diced watermelon has about 9 g of natural sugar, which is moderate. The sugar is spread across a large volume of water-rich fruit, so the glycemic load per serving is low.
How many calories are in a whole watermelon?
A whole melon (about 4,518 g by USDA) is roughly 1,355 calories total. That sounds like a lot, but it is also 10 pounds of fruit that no one eats alone in a sitting.
Keep going
Sources: Watermelon, raw (USDA FoodData Central, FDC ID 167765). Reviewed against USDA FoodData Central reference portions.
This page is for general educational purposes only and is not medical advice, diagnosis, or treatment. Nutrition values are estimates sourced from USDA FoodData Central and may vary by variety, preparation, and portion. Always consult a qualified healthcare professional before making significant changes to your diet.