Watermelon is the lowest-calorie fruit at 30 per 100g — over 90% water by weight. A wedge is around 85 calories and feels like a much bigger portion than its calorie count suggests. It's an underrated cutting-diet snack.
Calories scale with portion. Here's how a typical watermelon serving translates in your tracker:
Very low calorie — at 30 kcal per 100g, watermelon adds volume to a meal without meaningfully denting a calorie deficit.
How watermelon stacks up on calories and protein against foods people commonly compare it to:
Point your iPhone camera at watermelon and Spotwell's on-device AI estimates the portion and macros in under a second — no manual entry, no barcode hunting.
Download on theApp StoreWatermelon has approximately 30 calories per 100g. A typical serving — 1 cup, diced (152g) — comes in at 46 calories.
0.6g of protein per 100g. That puts watermelon at roughly 2.0g of protein per 100 calories — a useful lens when comparing to other fruits sources.
The simplest method: weigh it on a kitchen scale, then enter grams in your tracker. With Spotwell, you can skip the scale — point the camera at the plate and the AI estimates the portion in under a second. Adjust the value if it looks off.
It depends on your overall calorie target. Watermelon is naturally low-calorie at 30 kcal per 100g, so it's easy to fit into a deficit.