How much protein is in watermelon?

Watermelon has 0.6 g of protein per 100 g and 0.9 g per 1 cup, diced (152 g). That is 2 g of protein per 100 kcal — essentially not a protein source.

Where do these calorie figures come from?

USDA FoodData Central record 167765, “Watermelon, raw” (SR Legacy, FDC SR Legacy 2018-04 + FNDDS 2024-10-31). Energy is USDA nutrient 1008 (Energy, kcal); protein, fat and carbohydrate are read from the same record. USDA data is in the public domain, and the FDC ID above links straight to it.

All foods

Oranges, mango, pineapple and moreUSDA SR LegacyFDC 167765

Calories in watermelon

USDA FoodData Central record for “Watermelon, raw” — per 100 g, per every USDA serving size, and next to the other oranges, mango, pineapple and more rows.

The short answer

Watermelon: 30 kcal per 100 g. 1 cup, diced (152 g) is 46 kcal with 0.9 g of protein. Source: USDA FoodData Central record 167765, "Watermelon, raw".

Per 100 g

Nutrient	Per 100 g	Share of energy
Energy	30 kcal	100%
Protein	0.6 g	7%
Fat	0.2 g	5%
Carbohydrate	7.6 g	88%

Watermelon is 30 kcal per 100 g in USDA FoodData Central (SR Legacy). Of that energy, about 7% comes from protein, 5% from fat and 88% from carbohydrate. That works out to 2 g of protein per 100 kcal — essentially not a protein source.

Per serving

The serving sizes USDA lists for this record, priced from the per-100 g figures above. Nothing here is rounded to a “portion” — the gram weight next to each label is what the calories are computed from.

Serving	Weight	Calories	Protein	Fat	Carbs
100 g	100 g	30	0.6 g	0.2 g	7.6 g
1 cup, balls	154 g	46	0.9 g	0.3 g	11.7 g
1 cup, diced	152 g	46	0.9 g	0.3 g	11.6 g
1 wedge (approx 1/16 of melon)	286 g	86	1.7 g	0.6 g	21.7 g
10 watermelon balls	122 g	37	0.7 g	0.2 g	9.3 g
1 NLEA serving	280 g	84	1.7 g	0.6 g	21.3 g

Compared with other oranges, mango, pineapple and more

Food	kcal / 100 g	Protein / 100 g	Per serving
An orange	47	0.9 g	86 kcal · 1 large (3-1/16" dia)
A mango	60	0.8 g	202 kcal · 1 fruit without refuse
Pineapple	50	0.5 g	83 kcal · 1 cup, chunks
Watermelon	30	0.6 g	46 kcal · 1 cup, diced
A kiwi	61	1.1 g	42 kcal · 1 fruit (2" dia)
A pear	57	0.4 g	101 kcal · 1 medium
Medjool dates	277	1.8 g	66 kcal · 1 date, pitted

Worth knowing

Watermelon is 91% water and 30 kcal per 100 g, the lowest of the common fruits. A large wedge (~280 g) is about 85 kcal.

Other tables in fruits and fruit juices

The same numbers for the foods this one usually shares a plate — or a shopping list — with.

Questions about watermelon

How many calories are in watermelon?: Watermelon: 30 kcal per 100 g. 1 cup, diced (152 g) is 46 kcal with 0.9 g of protein. Source: USDA FoodData Central record 167765, "Watermelon, raw".
How much protein is in watermelon?: Watermelon has 0.6 g of protein per 100 g and 0.9 g per 1 cup, diced (152 g). That is 2 g of protein per 100 kcal — essentially not a protein source.
Where do these calorie figures come from?: USDA FoodData Central record 167765, “Watermelon, raw” (SR Legacy, FDC SR Legacy 2018-04 + FNDDS 2024-10-31). Energy is USDA nutrient 1008 (Energy, kcal); protein, fat and carbohydrate are read from the same record. USDA data is in the public domain, and the FDC ID above links straight to it.

How calorie.one logs it

Type “watermelon” into calorie.one and the app matches this exact record — “Watermelon, raw” — estimates the grams, and shows the line with its USDA label. You correct the amount; the per-100 g figure is never guessed. That split between recognition and arithmetic is the whole methodology. For the numbers in context, read How many calories are in a banana?.