Watermelon: Calories, Nutrition & Healthier Swaps
30 kcal per 100 g · Nutri-Score A
sugar: medium saturated fat: low salt: low fiber: low
Watermelon is over 90% water, so even a big slice is low in calories; its red flesh gets its color from lycopene.
Watermelon nutrition facts per 100 g and per serving
| Nutrient | Per 100 g | Serving: slice, 300 g |
|---|---|---|
| Calories | 30 kcal | 90 kcal |
| Protein | 0.6 g | 1.8 g |
| Fat | 0.2 g | 0.6 g |
| incl. saturated | 0 g | 0 g |
| Carbohydrates | 7 g | 21 g |
| incl. sugars | 6 g | 18 g |
| Fiber | 0.4 g | 1.2 g |
| Salt | 0 g | 0 g |
Values per 100 g as eaten, averaged from food composition tables (USDA FoodData Central and others) and rounded — a specific brand or recipe will differ a little.
Watermelon: nutrition highlights
It's light: 30 kcal per 100 g, so even a big serving barely moves your daily total.
On the open Nutri-Score algorithm, watermelon gets an A: one of the better picks in its category. The score weighs calories, sugar, saturated fat and salt against protein, fiber and the share of fruit, vegetables, legumes and nuts.
What to watch
- No red flags on the traffic light: sugar, salt and saturated fat per 100 g are all within the low-to-medium range.
How much movement is one serving?
One serving (slice, 300 g) is 90 kcal — roughly 29 min of easy walking or 11 min of cycling for a 70 kg (154 lb) person. In the diary, minutes are worked out for your weight and the activities you actually do.
Healthier swaps for Watermelon
Swaps are picked the same way the app does it: from the same kind of food, with a serving matched to the same calories (±25%), and only when the swap is clearly better — not “salad instead of pizza”.
- Guava — 150 g, 90 kcal: +6.9 g fibre.
- Blackberries — 250 g, 90 kcal: −5.8 g sugar, +12 g fibre.
- Kumquat — 150 g, 90 kcal: +8.6 g fibre.
- Blackcurrants — 200 g, 88 kcal: +8.4 g fibre.
More in fruit & berries
AppleBananaOrangeGrapesPearKiwiPineappleMangoPomegranateStrawberries