Is Watermelon keto?
Not keto-friendly 10.9 g net carbs per one cup of cubes (152 g) — 55% of a 20 g keto day.
Short answer: Not in normal portions. One cup of cubes (152 g) of watermelon: 10.9 g net carbs — 55% of a strict 20 g keto day — with 0.3 g fat and 0.9 g protein.
Watermelon is about 90% water, so its carbs per gram look low. The catch is portion size: a typical wedge is several hundred grams and almost none of the carb is fibre.
How watermelon fits a keto carb budget
On a 20 g day, one serving uses 55% of your budget, leaving 9.1 g for everything else. Measure portions rather than eyeballing them.
Worked example. 152 g of watermelon = 11.6 g total carbs − 0.6 g fibre = 10.9 g net carbs, 0.3 g fat, 0.9 g protein and 46 kcal.
If you still want some, plan it: a strict day is 20 g, and how net carbs are counted explains why the fibre here does not rescue it.
Nutrition facts
| Nutrient | Per 100 g | Per one cup of cubes (152 g) |
|---|---|---|
| Calories | 30 kcal | 46 kcal |
| Fat | 0.2 g | 0.3 g |
| Protein | 0.6 g | 0.9 g |
| Total carbohydrate | 7.6 g | 11.6 g |
| Fibre | 0.4 g | 0.6 g |
| Net carbs | 7.2 g | 10.9 g |
Where the energy comes from:
How to eat watermelon on keto
- A small cup of cubes can fit on a hot day if the rest of the day is very low.
- Cucumber with mint and lime gives a similar cooling effect.
Lower-carb swaps
| Swap | Net carbs / serving | Saves |
|---|---|---|
| Strawberries (five large strawberries) | 5.1 g | 5.8 g |
| Cucumber (one cup sliced) | 3.2 g | 7.7 g |
Compared with other fruits
Watermelon ranks #8 of 15 fruits in our database by net carbs per 100 g (lowest first). Berries and avocado fit; most sweet fruit uses a whole day of carbs in one serving.
| Food | Net carbs / 100 g | Per serving |
|---|---|---|
| Avocado | 1.8 g | 1.3 g |
| Olives | 3.1 g | 1.4 g |
| Blackberries | 4.3 g | 3.1 g |
| Raspberries | 5.4 g | 3.3 g |
| Strawberries | 5.7 g | 5.1 g |
| Coconut (fresh flesh) | 6.2 g | 2.8 g |
See all fruits ranked by net carbs →
Frequently asked questions
How many net carbs are in watermelon?
Watermelon has about 7.2 g of net carbs per 100 g (7.6 g total carbohydrate minus 0.4 g fibre), and about 10.9 g per one cup of cubes (152 g).
Can you eat watermelon on keto?
Not in normal portions. One one cup of cubes contains 10.9 g net carbs, 55% of a strict daily limit.
Values are per 100 g of the raw or stated food, rounded, from USDA FoodData Central. Brands and varieties differ — check the label for packaged products.