Calories in Watermelon: Nutrition Facts by Serving Size

Watermelon is one of the most hydrating, lowest-calorie fruits you can eat. At 92% water and only 30 calories per 100 grams, it is the ultimate high-volume, low-calorie snack. It is also a surprising source of lycopene, vitamin C, and the amino acid citrulline.

Calories by serving size:

Watermelon is one of the richest food sources of lycopene — a carotenoid antioxidant also found in tomatoes. One cup provides roughly 6,890 mcg of lycopene, which supports heart health and skin protection.

Frequently Asked Questions (FAQ)

How many calories are in a cup of watermelon?

One cup of diced watermelon (about 152 grams) contains approximately 46 calories. It provides 11 grams of carbohydrates and 9 grams of natural sugar. Despite the sweetness, watermelon is extremely low in calories because it is 92% water by weight.

Is watermelon good for weight loss?

Watermelon is excellent for weight loss due to its extremely low calorie density. You can eat a large volume for very few calories, which helps you feel full and satisfied. Research shows that foods with high water content promote satiety and reduce overall calorie intake at meals. A two-cup serving of watermelon is only 92 calories but physically fills you up.

Is watermelon high in sugar?

Watermelon contains about 6 grams of sugar per 100 grams, which is lower than most fruits. However, it has a glycemic index of about 72, which is relatively high. The important metric is glycemic load, which accounts for the actual amount of carbs per serving. Watermelon's glycemic load per cup is only about 5 (low), because each serving contains relatively few total carbohydrates.

What is citrulline in watermelon?

Citrulline is an amino acid found in high concentrations in watermelon, especially in the rind. Your body converts citrulline to arginine, which helps produce nitric oxide — a compound that relaxes blood vessels and improves blood flow. Studies suggest watermelon consumption can reduce muscle soreness and slightly lower blood pressure.

How should I store watermelon for maximum nutrition?

Store uncut watermelon at room temperature. Research from the USDA found that watermelon stored at room temperature develops up to 40% more lycopene and 139% more beta-carotene than refrigerated watermelon. Once cut, refrigerate and consume within 3–5 days. Cut watermelon stored too long loses vitamin C and develops off-flavors.