How Many Calories in Watermelon?

Calories in Watermelon (Per 100g, Per Cup, Per Wedge)

Watermelon is one of the lowest-calorie foods on earth. One cup of diced watermelon (152g) has just 46 calories, 11.5g carbs, and 9.4g of natural sugar. Per USDA FoodData Central, raw watermelon provides 30 kcal per 100g — making it the lowest-calorie common fruit alongside strawberries. Watermelon is 91% water, which is why a large serving fills you up for so few calories. It is also the richest whole-food source of lycopene (4,532 mcg per 100g — more than raw tomato), an antioxidant linked to heart and skin health. These are generic USDA values — varieties vary slightly.

Why Watermelon Is So Low in Calories (and Still Filling)

Watermelon has an energy density of just 0.30 calories per gram — the lowest of any common fruit. The reason is simple: 91% of a watermelon's weight is water. This means you can eat a generous portion (1 cup, 152g) for only 46 calories and feel just as full as you would from a 200-calorie snack of nuts or cheese. A 2019 study in the journal Nutrients found that adults who ate 2 cups of watermelon daily for 4 weeks felt significantly more satiated, consumed fewer total calories, and had lower body weight and blood pressure compared to a control group eating low-fat cookies. The fiber (0.6g per cup) and water volume work together to stretch the stomach and trigger fullness signals.

🍉 Full Nutrition Facts — Raw Watermelon (Per 100g and Per Cup Diced 152g)

Complete nutrition facts for raw watermelon, based on USDA FoodData Central reference values. Watermelon is the richest whole-food source of lycopene and provides meaningful vitamin C and potassium.

🍉 Watermelon Calories by Portion — Per 100g, Per Cup, Per Wedge

Seedless vs seeded: Nutrition is essentially identical — seedless watermelon has the same calories, sugar, and lycopene as seeded. The seeds themselves are edible and rich in magnesium and protein, but most people spit them out. Watermelon juice: A cup (240ml) has about 71 calories and 18g sugar — juicing removes the fiber and concentrates the sugar, so whole fruit is the better choice for weight loss.

🍉 Watermelon vs Cantaloupe vs Honeydew — Full Comparison (Per 100g)

All three melons are low in calories, but they differ in key nutrients. Watermelon has the fewest calories (30 per 100g) and the most lycopene. Cantaloupe has the most vitamin C (36.6mg) and vitamin A (169 mcg — 19% DV). Honeydew is in the middle on calories (36) and has the most potassium (228mg). For weight loss, watermelon wins on calories; for vitamin A and C, cantaloupe wins; for potassium, honeydew wins. All three are excellent choices.

Practical Tips for Eating Watermelon

• Pre-portion it: A whole melon is hard to eyeball. Dice it into 1-cup containers (46 cal each) right when you bring it home. This prevents accidentally eating half a melon (750+ calories).
• Eat the whole fruit, not the juice: A cup of juice (71 cal, 18g sugar) has 50% more calories and double the sugar per cup than diced watermelon (46 cal, 9.4g sugar). The fiber in whole fruit slows the sugar absorption.
• Pair with protein: Watermelon is mostly carbs and water. Pair 1 cup (46 cal) with a half-cup of cottage cheese (90 cal, 12g protein) for a 136-calorie snack with 13g protein that keeps you full for hours.
• Freeze the rest: Cut leftover watermelon into cubes and freeze them. Frozen watermelon cubes make a great low-calorie popsicle alternative or can be blended into a smoothie with no ice needed.
• Eat it cold for maximum lycopene: Lycopene in watermelon is actually more bioavailable when the fruit is at room temperature, but the difference is small. The bigger win is simply eating watermelon regularly — it is the richest whole-food source of lycopene.

Watermelon and Weight Loss — Next Steps

Watermelon is one of the best fruits for weight loss — the lowest energy density of any common fruit and proven satiety benefits. Here's how to use it effectively:

• Use it as a high-volume, low-calorie snack: 2 cups of watermelon (92 calories) is the same calories as a single ounce of almonds (164 calories) — but 14 times the volume. For hunger between meals, watermelon is hard to beat.
• Replace higher-calorie fruits: A cup of grapes (104 cal) or a medium banana (105 cal) has more than double the calories of a cup of watermelon (46 cal). Swap them for watermelon to cut 60+ calories per serving.
• Watch the toppings: A plain cup of watermelon is 46 calories. Adding feta cheese (75 cal per oz) or a drizzle of honey (64 cal per tbsp) can double that. Enjoy it plain or with a measured protein pairing.
• Don't fear the sugar: At 9.4g per cup, watermelon has less sugar than an apple (19g) or a banana (14g). The glycemic load per cup is only about 5 — low. The 91% water content dilutes the sugar so much that the real blood sugar impact is minimal.

For your daily calorie and protein targets, use the Calorie Calculator and Protein Calculator. This is not medical advice — talk to your doctor.

Ask Lana

The questions everyone asks

Real answers, like a friend would give them — warm, honest, and always with your next tiny step.

Is watermelon good for weight loss?

Yes — at 46 calories per cup and 91% water, it is the lowest-calorie common fruit. A 2019 study found eating 2 cups daily reduced overall calorie intake and body weight. This is not medical advice — talk to your doctor.

Does watermelon have too much sugar?

How do I track it?

Educational only — not medical advice. Talk to your doctor.

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