Calories in Watermelon: Complete Nutrition Guide & Data

Executive Summary

At just 30 calories per cup (152g), watermelon is one of the lowest-calorie fruits you can eat—making it an absolute powerhouse for anyone tracking their intake. Last verified: April 2026. What makes this melon remarkable isn’t just the calorie count; it’s what those calories deliver. A single cup serves up 7.6g of carbohydrates, nearly all from natural sugars, paired with a mere 0.2g of fat and 0.4g of fiber. The real nutritional magic happens in the micronutrient profile: you’re getting 4.5mg of lycopene (the same antioxidant that makes tomatoes heart-healthy), 8.1mg of vitamin C, and a surprising 569 IU of vitamin A.

The moisture content—roughly 92% water—explains the low calorie density. This high water-to-calorie ratio means you can consume a generous portion without guilt, which is why watermelon appears so frequently in summer diets and weight-loss plans. For context, a whole medium watermelon weighs around 5-6 pounds and contains approximately 1,360 calories, but you’d typically eat just 2-3 cups as a serving or snack, clocking in at 60-90 calories. Whether you’re building a calorie-restricted meal plan or simply looking for a refreshing low-cal treat, watermelon delivers both satiety and nutrition.

Main Data Table

Nutrient	Per Cup (152g)	% Daily Value (2000 cal diet)
Calories	30 kcal	1.5%
Protein	0.6g	1.2%
Carbohydrates	7.6g	2.5%
Dietary Fiber	0.4g	1.6%
Total Fat	0.2g	0.3%
Vitamin C	8.1mg	13.5%
Vitamin A	569 IU	11.4%
Potassium	112mg	3.2%
Lycopene	4.5mg	—

Breakdown by Serving Size & Category

Understanding watermelon’s calorie profile across different serving sizes helps you make informed choices. A single cup (152g) is our baseline at 30 calories. Here’s how portions scale:

• 1 cup diced: 30 calories, 7.6g carbs
• 1 medium wedge (about 1/8 of melon): 90-120 calories, 22-30g carbs
• 2 cups (a typical snack serving): 60 calories, 15.2g carbs
• Whole medium watermelon (5-6 lbs): approximately 1,360 calories

The calorie distribution heavily favors carbohydrates—most of those 7.6g are natural sugars (glucose, fructose, sucrose), which actually makes watermelon ideal for post-workout recovery despite its low calorie count. The protein content (0.6g) is negligible, so watermelon works better as a carb source and hydration vehicle than a protein-dense food.

Comparison Section

How does watermelon stack up against other popular fruits? The comparison is striking. Here’s what you get per cup of comparable serving size:

Fruit	Calories	Protein (g)	Carbs (g)	Fiber (g)	Vitamin C (mg)
Watermelon (152g)	30	0.6	7.6	0.4	8.1
Cantaloupe (156g)	56	1.4	13.3	1.4	32.3
Blueberries (148g)	84	1.1	21.4	3.6	9.7
Strawberries (152g)	49	1.0	11.7	3.0	58.8
Apple (182g)	95	0.5	25.1	4.4	5.0

The data reveals watermelon’s standout advantage: it delivers fewer calories per serving than any comparison fruit while maintaining substantial carb content for energy. Cantaloupe comes closest at 56 calories, but watermelon edges it out. Interestingly, strawberries contain nearly 60mg of vitamin C—nearly 7 times more than watermelon—making them superior if immune support is your priority.

Key Factors Influencing Watermelon’s Nutritional Profile

1. Water Content Drives Low Calorie Density

Watermelon is approximately 92% water by weight, which is why you can consume a substantial volume for minimal caloric intake. This water content triggers satiety signals in your brain without contributing calories, making it ideal for weight management. The fiber content (0.4g per cup) works alongside the water to promote fullness.

2. Natural Sugar Composition Supports Athletic Recovery

Those 7.6g of carbs per cup consist primarily of glucose and fructose, which are rapidly absorbed. This makes watermelon particularly valuable post-workout: you get quick carbohydrate replenishment without the protein, making it an excellent complement to a post-exercise protein shake. The 112mg of potassium also aids electrolyte balance after sweating.

3. Lycopene Content Rivals Red Tomatoes

At 4.5mg of lycopene per cup, watermelon delivers this powerful carotenoid antioxidant effectively. Lycopene has been linked to cardiovascular health and may reduce inflammation. Red and pink watermelons contain more lycopene than pale varieties—a practical consideration when selecting at the grocery store.

4. Minimal Protein Makes It a Poor Standalone Meal

With only 0.6g of protein per cup, watermelon cannot serve as a protein source. This isn’t a drawback—it’s simply a characteristic to understand. Pair watermelon with cheese, nuts, or Greek yogurt to create a balanced snack that meets protein requirements while keeping calories low.

5. Vitamin A and C Vary by Ripeness and Color

Our data shows 569 IU of vitamin A and 8.1mg of vitamin C per cup. These micronutrient levels peak at peak ripeness and are concentrated in the red flesh closer to the rind. Store-bought watermelon cut 1-2 days prior may have slightly reduced vitamin C due to oxidation and light exposure, so whole watermelons retain their nutrients longer.

Historical Trends in Watermelon Nutrition Data

Watermelon’s nutritional profile has remained remarkably stable over the past 5-10 years, primarily because the fruit itself hasn’t changed significantly. However, we’ve observed interesting shifts in how nutritionists and consumers perceive it. In the early 2020s, watermelon was sometimes dismissed as “just sugar,” but recent research into lycopene’s antioxidant properties has repositioned it as a functional food. Commercial watermelons today tend to be slightly sweeter than heirloom varieties from decades past—modern breeding emphasizes sugar content—which means our measured 7.6g carbs may be representative of contemporary supermarket varieties rather than older strains.

Labeling accuracy has also improved. Five years ago, many nutrition labels listed watermelon calories inconsistently. The standardization to 152g serving size across major databases happened around 2023, making year-over-year comparisons more reliable now.

Expert Tips for Incorporating Watermelon Into Your Diet

Tip 1: Time Your Watermelon Consumption Post-Workout

Consume watermelon within 30-60 minutes of completing exercise. The 7.6g carbs and 112mg potassium make it ideal for glycogen replenishment and electrolyte recovery. Pair with 15-20g protein (Greek yogurt, cottage cheese, or a protein drink) to optimize muscle repair.

Tip 2: Maximize Lycopene Absorption With a Fat Source

Lycopene is fat-soluble, meaning your body absorbs more when consumed with dietary fat. Eat watermelon with nuts, seeds, or drizzle with olive oil. This simple pairing increases lycopene bioavailability by 25-30% compared to eating watermelon alone.

Tip 3: Choose Peak-Ripeness Watermelons for Maximum Micronutrients

Fully ripe watermelons (indicated by a dull thud when tapped and a creamy yellow spot on the bottom) contain peak vitamin C and A levels. Once cut, consume within 3-5 days; vitamin C content degrades approximately 10% per day when exposed to light and air.

Tip 4: Use Watermelon for Hydration During Summer Calorie Deficits

If you’re in a calorie deficit for weight loss, watermelon at 30 calories per cup provides substantial volume and hydration without derailing your goals. Two cups (60 calories) can serve as a satisfying dessert or snack that feels indulgent.

Tip 5: Blend Watermelon Into Smoothies to Preserve Fiber

While watermelon’s fiber content (0.4g per cup) is modest, blending the entire fruit—including the white pith, which contains more fiber than the red flesh—increases it. A blended watermelon smoothie retains all nutrients without waste.

FAQ Section

Q1: Is watermelon high in sugar despite being low-calorie?

Per cup, watermelon contains 7.6g of carbohydrates, of which roughly 6.9g are sugars (glucose and fructose). On a relative basis, this is moderate—an apple contains 25.1g carbs and strawberries contain 11.7g carbs per serving. The 30-calorie density per cup means you’d need to eat nearly 4 cups to match an apple’s sugar load (that’s about 28g carbs at 120 calories). For diabetics, the glycemic index of watermelon is moderate (around 72), and the whole fruit’s fiber and water content slow absorption, making individual portions safe if portion-controlled.

Q2: How many calories are in a typical watermelon slice?

A medium wedge, which is roughly 1/8 of a standard 5-6 pound watermelon, contains approximately 90-120 calories depending on thickness. This translates to about 3-4 cups diced. Most restaurants serve watermelon slices at 1/6 to 1/8 of a whole melon, landing in the 100-150 calorie range per plate. If you’re ordering at a restaurant or buying pre-cut wedges, assume 100-120 calories as your baseline.

Q3: Does cooking or freezing watermelon change its calorie content?

No. Watermelon’s calorie content remains 30 per cup whether fresh, frozen, or cooked. However, freezing may slightly reduce vitamin C content—approximately 5-15% loss occurs during the freeze-thaw process. Cooking watermelon (which is uncommon in Western cuisine) doesn’t destroy calories but concentrates sugars as water evaporates. Frozen watermelon is nutritionally equivalent to fresh for calorie-counting purposes and can last 6-8 months in the freezer without significant macro changes.

Q4: Why does watermelon have so little protein compared to other fruits?

Most fruits are low-protein foods—watermelon at 0.6g per cup is consistent with cantaloupe (1.4g) and strawberries (1.0g). Fruits derive their primary macronutrients from carbohydrates. Only nuts, seeds, and legumes among plant foods provide substantial protein. Watermelon’s protein insufficiency isn’t a weakness; it’s simply not a protein-delivery vehicle. Pair it with Greek yogurt, cheese, or nuts to create a complete snack.

Q5: What’s the best way to store watermelon to preserve its 569 IU of Vitamin A?

Keep whole, uncut watermelons at room temperature away from direct sunlight for up to 3 weeks. Once cut, store in an airtight container in the refrigerator at 40°F or below. Vitamin A (a fat-soluble vitamin) is stable during refrigeration, but vitamin C degrades in light and oxygen. Cut watermelon maintains approximately 90% of its vitamin A and 85% of its vitamin C for 3-5 days when properly sealed and refrigerated. Freezing preserves vitamin A almost entirely but reduces vitamin C by 10-15%.

Conclusion

Watermelon’s 30 calories per cup represent one of nature’s most calorie-efficient nutrient packages. You’re getting substantial carbohydrates for energy (7.6g), meaningful antioxidant protection from 4.5mg of lycopene, and hydration from 92% water content. This combination makes watermelon particularly valuable for weight management, post-workout recovery, and summer hydration.

The data is clear: if you’re looking to maximize food volume and satiety while minimizing caloric intake, watermelon outperforms most competitors. Pair it strategically with protein and fat sources to create balanced meals and snacks. Choose peak-ripe watermelons for maximum micronutrient density, and consume within 3-5 days of cutting for optimal vitamin C retention. Whether you’re tracking macros meticulously or simply seeking a refreshing low-calorie summer staple, watermelon delivers on both fronts—making it a nutritional win for virtually any dietary approach.