Calories in Watermelon

Updated July 2026 · Reviewed by CaloriesCalc Team · Source: USDA FoodData Central

30
kcal
per 100g
7.55
g
Carbs
0.61
g
Protein
0.15
g
Fat
0.4
g
Fiber
86
kcal per wedge (286g)
46
kcal per cup diced (152g)
9
kcal per oz (28g)
✔ Ultra low calorie✔ 92% water content✔ Rich in lycopene✔ Fat free✔ Gluten free✔ Vegan
Watermelon nutrition facts and calories per 100g
🍉92% water — most hydrating fruit
🔴Highest lycopene content of any fruit
💊Contains citrulline for muscle recovery
❤️Supports heart health
🛡Source of vitamin C & A
🔥Only 30 kcal per 100g

🍉 Calculate Calories for Any Watermelon Weight

Weight100g

Nutrition Facts

Per 100g (raw watermelon)

* % Daily Value based on a 2,000 kcal diet.


Quick summary: Watermelon contains just 30 calories per 100g — one of the lowest of any fruit. At 92% water content it is the most hydrating common fruit. A cup of diced watermelon provides 46 calories, 11% of daily vitamin A, 9% of vitamin C, and 7.6mg of lycopene — the highest of any common fruit. It also contains citrulline, an amino acid that improves blood flow and reduces muscle soreness after exercise.

Vitamins & Minerals — per 100g

NutrientAmount% Daily ValueBar
Vitamin A569 IU11%
Vitamin C8.1 mg9%
Lycopene7.6 mgAntioxidant
Potassium112 mg2%
Vitamin B60.05 mg3%
Magnesium10 mg2%
Thiamine (B1)0.03 mg3%
Copper0.04 mg4%
Calcium7 mg1%
Phosphorus11 mg1%

Calories in Watermelon by Weight

WeightCaloriesCarbsProteinFat

Calories in Different Watermelon Servings

ServingWeightCaloriesCarbsNet CarbsFat
1 cup diced152g46 kcal11.5g11.2g0.6g
1 wedge (⅛ melon)286g86 kcal21.6g21.0g1.1g
1 oz28g8 kcal2.1g2.0g0.1g
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Macronutrient Breakdown — per 100g

Carbohydrates7.55g · 87% of calories
Protein0.61g · 8% of calories
Fat0.15g · 4% of calories
Fiber0.4g (included in carbs)

Watermelon is 92% water — the highest water content of any common fruit. Its carbs are almost entirely simple sugars with very little fiber (0.4g/100g). This gives it a high glycemic index but very low glycemic load due to its low calorie density.

Micronutrient Highlights

🔴
Lycopene
7.6 mg
Antioxidant
Highest of any common fruit — heart & prostate health
🛡
Vitamin C
8.1 mg
9% Daily Value
Immune support & collagen synthesis
👁
Vitamin A
569 IU
11% Daily Value
Vision, immune function, skin health
💊
Citrulline
~250 mg
Amino acid
Muscle recovery & blood flow
Potassium
112 mg
2% Daily Value
Electrolyte balance & heart function
💧
Water
92%
Extreme hydration
Most hydrating common fruit

Watermelon Health Benefits & Nutrition

Lycopene — the Red Antioxidant

Watermelon contains 7.6mg of lycopene per 100g — the highest concentration of any commonly consumed fruit, higher even than tomatoes (2.5mg/100g raw). Lycopene is a carotenoid antioxidant associated with reduced risk of prostate cancer, cardiovascular disease, and UV-induced skin damage. Unlike tomatoes, watermelon lycopene is more bioavailable in its raw form without cooking.

Citrulline and Athletic Performance

Watermelon is uniquely rich in L-citrulline — a non-essential amino acid found in the flesh and particularly the rind. Citrulline is converted to arginine in the body, which increases nitric oxide production and dilates blood vessels. Studies show watermelon juice before exercise reduces muscle soreness by 40% compared to placebo, and may improve time to exhaustion by 7–10% in endurance athletes.

Hydration and Heat Management

At 92% water content, watermelon is effectively a solid beverage. A 2-cup serving provides approximately 285ml of water alongside electrolytes (potassium, magnesium), making it more effective for hydration than plain water because the natural sugars and electrolytes facilitate cellular water uptake. This makes watermelon particularly valuable in hot weather and post-exercise recovery.

Glycemic Index vs Glycemic Load — an Important Distinction

Watermelon has a high glycemic index of approximately 76, which concerns some people with blood sugar conditions. However, its glycemic load per serving is actually very low (GL≈5 per cup) because it has so few carbohydrates per serving. A person with diabetes can typically eat 1–2 cups of watermelon without significant blood sugar impact — the GL matters more than the GI for real-world blood sugar management.

Is Watermelon Suitable for Your Diet?

Weight loss
Excellent — 30 kcal/100g
Keto
No — high GI, 7.1g net carbs
Vegan
Yes
Paleo
Yes
Gluten-free
Yes
⚠️
Diabetic
1 cup max — watch portions
Low-FODMAP
Up to 2 cups
Mediterranean
Yes

Frequently Asked Questions

How many calories in watermelon?
Watermelon contains 30 calories per 100g. A cup of diced watermelon (152g) has 46 calories. A standard wedge (⅛ of a melon, 286g) has 86 calories. Use the slider above to calculate for any weight.
Is watermelon good for weight loss?
Yes — watermelon is one of the best foods for weight loss. At 30 kcal per 100g with 92% water content, it provides enormous volume per calorie. A large 2-cup serving is only 92 calories but takes up significant stomach volume, reducing appetite. Its natural sweetness also helps satisfy sugar cravings.
Is watermelon high in sugar?
Moderately. Watermelon contains 6.2g of natural sugar per 100g — less than grapes (15.5g) or bananas (12.2g). A 2-cup serving contains about 19g of sugar. While the GI is high (~76), the glycemic load per cup is only about 5, making it less impactful on blood sugar than its GI suggests.
Is watermelon keto?
No. Watermelon has 7.1g of net carbs per 100g and a high glycemic index. It's not suitable for strict keto. A very small portion (50g, ~15 calories) might technically fit, but it's not practical or satisfying.
What is lycopene in watermelon?
Lycopene is a red carotenoid antioxidant that gives watermelon its characteristic colour. Watermelon contains 7.6mg per 100g — more than any other common fruit. Lycopene is associated with reduced prostate cancer risk, lower cardiovascular risk, and protection against UV skin damage. Unlike tomatoes, watermelon lycopene is fully bioavailable without cooking.
Is watermelon good for hydration?
Extremely. At 92% water content, watermelon is the most hydrating common fruit. It also contains potassium and magnesium that help maintain electrolyte balance. Research shows fruits with high water content improve overall hydration status more effectively than drinking the equivalent amount of plain water.

Nutrition values sourced from USDA FoodData Central. Values are averages and may vary. Not medical advice.