How many calories in a melon? Slice, half and whole

In summer, melon gets eaten by the slice, standing at the kitchen counter, or as a starter with a few thin slices of ham. Nobody weighs it, yet the question comes back every year: how many calories? Food composition tables give a more nuanced answer than the single number search engines show.

For American cantaloupe, the USDA lists 34 kcal per 100 g of flesh, with 7.9 g of sugars and 90 g of water. Norway’s Matvaretabellen reuses these analyses but recalculates the energy its own way, which gives 38 kcal. Ciqual, the French food composition table run by the food safety agency ANSES and updated at the end of 2025, analysed a Charentais-type cantaloupe and found 60 kcal per 100 g, with 10.6 g of sugars and only 84 g of water.

Why such a gap? Melon contains almost no fat or protein, about 1 to 1.6 g of both combined per 100 g. Its calories therefore come almost entirely from its sugars. A sweeter melon is a more caloric melon, and the Charentais analysed in France was clearly sweeter than the American cantaloupe.

A melon is sold whole, but you only eat about half of it. According to the USDA, the rind makes up 39% of a cantaloupe’s weight, the seeds and fibres in the cavity 9% and cutting losses 1%: 49% of the melon ends up in the bin. Matvaretabellen reaches the same result, with an edible part of 51%.

A 1 kg melon therefore gives about 510 g of flesh. Cut into eight, each slice holds about 65 g of flesh; Matvaretabellen uses 55 g for a slightly thinner slice. The table gives both ends of the range: the USDA’s low base (34 kcal per 100 g) and the high base of Ciqual’s Charentais (60 kcal).

A Charentais melon can weigh anything from one to three times as much as another. The specification for the protected Melon de Cavaillon (PGI) accepts fruit from 550 g to 1.75 kg for sale as fresh produce, and France’s Label Rouge quality scheme requires at least 600 g. The table starts from the weight on the shop scale, rind included, and applies the 51% edible part.

These specifications also set a minimum sugar level: at least 13 °Brix for every Label Rouge melon and on average for Melon de Cavaillon, against 10 °Brix for the standard Charentais that Label Rouge compares itself with. Degrees Brix, measured with a refractometer, roughly match the grams of dissolved sugars in 100 g of juice. A melon with one of these labels therefore sits towards the top of the calorie range.

The orange-fleshed Charentais is not the only melon in the shops. Honeydew, with pale green flesh, and galia, with a netted rind and green flesh, have their own entries in the tables. The most recent values come from Danish analyses published in 2023 and used by Matvaretabellen: 31 kcal per 100 g for honeydew, 32 kcal for galia. The USDA gives 36 kcal for honeydew.

Ciqual lists only 22 kcal for honeydew, but its sample contained half as much sugar as the others (4.3 g per 100 g, against 7 to 8 g), so treat that figure as a minimum. Yellow (canary) melon, the green Spanish piel de sapo and other varieties have no entry of their own in these three tables. Without a published value, the 35 kcal per 100 g rule remains the best estimate.

What about watermelon? It belongs to a different species from melon (Citrullus lanatus versus Cucumis melo, according to the USDA). With 30 to 36 kcal per 100 g depending on the table, it is as light as an ordinary melon and clearly lower than Ciqual’s Charentais (35 kcal against 60 in the same table). Slice-by-slice figures are in our guide on watermelon calories.

With 8 to 11 g of sugars per 100 g of orange flesh depending on the table (about 7 g for honeydew and galia according to Matvaretabellen), melon is a sweet fruit: half a 1 kg Charentais provides 20 to 27 g. In Ciqual’s Charentais, sucrose dominates (6.6 g), followed by fructose (2.5 g) and glucose (1.5 g); the USDA’s cantaloupe follows the same pattern, with 4.4 g of sucrose.

These sugars do not count as “free sugars”, the ones the World Health Organization (WHO) recommends limiting. Its definition covers sugars added by the manufacturer, cook or consumer, and those naturally present in honey, syrups and fruit juices, not the sugars in a whole fruit. Melon juice or a melon smoothie, on the other hand, does fall into that category.

Melon’s glycemic index is high for a fruit: 65 to 70 for cantaloupe tested in Australia, according to the international tables published in 2008, against 40 for strawberries in the same tables. But a 120 g portion contains only 6 g of available carbohydrate, hence a glycemic load of just 4. The load takes into account the amount you actually eat: our guide on the glycemic index explains the difference between the two. Fibre stays modest: 0.9 to 1.3 g per 100 g.

Melon is mostly water: 84 to 90 g per 100 g depending on the table. Half a 1 kg melon therefore provides 215 to 230 g of water, which counts towards your daily intake: our guide on hydration explains how much of your water comes from food.

Its orange colour comes from beta-carotene, which the body turns into vitamin A: 2,000 to 2,500 µg per 100 g according to the USDA and Ciqual, against only 30 µg in green-fleshed honeydew. A 150 g portion of Charentais provides more than 3 mg.

For vitamin C, the tables disagree. The USDA and Matvaretabellen count 37 mg per 100 g of cantaloupe, close to half the EU reference value of 80 mg a day, but Ciqual’s Charentais sample contained only 8 mg. Honeydew provides 14 to 18 mg.

Finally, melon supplies 270 to 380 mg of potassium per 100 g. According to the WHO, a potassium intake of at least 3,510 mg a day may be beneficial for adults, and fresh fruit and vegetables are a way to get more of it. It also recommends at least 400 g of fruit and vegetables a day from the age of 10: half a melon alone covers more than half of that.

Melon on its own is light; it is what goes with it that adds up. Cured ham has 239 kcal per 100 g in the Ciqual table (248 for Parma ham, 235 for serrano), as much as 4 to 7 times its weight in melon. A thin slice of dry-cured ham weighs about 8 g according to Matvaretabellen: five slices, or 40 g, add nearly 100 kcal to the plate.

Salt deserves a look too. With 5.7 g of salt per 100 g according to Ciqual, those 40 g of cured ham provide 2.3 g of salt, almost half the WHO’s maximum of 5 g a day. Melon with port, another classic, mainly adds alcohol and sugar: 4 cl of sweet fortified wine comes to about 60 kcal.

Melon has real strengths when you are watching your weight: lots of water, few calories for a large volume and a sweet taste that can replace a richer dessert. A 160 g cup of cubes provides 55 to 95 kcal for a volume that genuinely fills a bowl. That does not make it a “zero calorie” food: our guide on zero calorie foods explains why negative calories are a myth. Counting mistakes mostly come from four oversights.

100 g of melon flesh provides about 35 kcal for an ordinary cantaloupe and up to 60 kcal for a very sweet Charentais, with the gap coming almost entirely from sugar. You only eat about half of a melon: a slice comes to 20 to 40 kcal, half a 1 kg melon to 85 to 150 kcal and the whole melon to 175 to 305 kcal. According to the USDA and Matvaretabellen, honeydew, galia and watermelon stay around 30 to 36 kcal per 100 g. Melon mainly provides water, beta-carotene if it is orange, and potassium, and its sugars do not count as free sugars as long as you eat it whole. It is the cured ham, port and feta that turn a starter of around a hundred calories into one of 250 kcal.