How Much Sugar Is in Watermelon?
A cup of watermelon has about 9 g of sugar — it tastes very sweet but is over 90% water, so the sugar per bite is low.
Moderate sugar
9g sugar
in 1 cup diced (152 g) · about 2.1 teaspoons
- Per serving
- 9 g
- Per 100 g
- 6 g
- Type
- Natural sugar
- In teaspoons
- ≈ 2.1 tsp
Fine in a portion — worth keeping an eye on.
Watermelon tastes intensely sweet, so people assume it's loaded with sugar. In fact a cup has only about 9 g — it's more than 90% water, which dilutes the sugar and makes it one of the most hydrating, lower-sugar fruits by volume.
The one nuance is glycemic index: watermelon's sugar is fast-releasing, so pairing it with a little protein (feta, yogurt) steadies things if you're watching blood sugar.
Lower-sugar swaps
- Pair with a few cubes of feta or a spoon of yogurt to slow the sugar
- Freeze into cubes for a near-zero-effort sweet snack
Frequently asked questions
- Why does watermelon taste so sweet if it's low in sugar?
- Its sugar is mostly fast-releasing fructose and it has almost no competing flavours, so it reads as very sweet despite only ~6 g per 100 g.
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Sugar values from USDA FoodData Central; actual amounts vary by brand, ripeness, and recipe. Last updated 2026-07-21.