One cup of cubed cantaloupe (160 grams) contains about 13 grams of total carbohydrates. With only 1.4 grams of fiber per cup, the net carb count comes to roughly 11.5 grams, making cantaloupe one of the lower-carb fruits you can choose.
Carbs by Serving Size
How many carbs you’re getting depends entirely on how much cantaloupe you eat, and portions vary a lot with this fruit. A half cup of diced cantaloupe has about 6.5 grams of carbs. A full cup of cubes, which is the standard serving size, has 13 grams. That full cup also contains about 13 grams of sugar, which accounts for nearly all the carbohydrate content. The remaining carbs come from a small amount of fiber (about 1.4 grams).
For context, a typical medium wedge (one-eighth of a whole melon) falls close to that one-cup measurement. If you’re slicing up an entire cantaloupe and eating it over a few sittings, each eighth gives you a similar carb count to a cupped handful of cubes.
Net Carbs for Low-Carb and Keto Diets
Net carbs are calculated by subtracting fiber from total carbohydrates, since fiber doesn’t raise blood sugar. For one cup of cantaloupe, that’s roughly 13 minus 1.4, giving you about 11.5 grams of net carbs.
If you’re following a keto diet that caps net carbs at 20 to 50 grams per day, a full cup of cantaloupe takes up a meaningful chunk of that budget. A half-cup serving (around 5 net carbs) is more realistic for strict keto. Michigan State University Extension lists cantaloupe among fruits with 15 grams or fewer of carbs per serving, which places it in the lower range for fruit overall.
How Cantaloupe Compares to Other Melons
Cantaloupe and watermelon are close in carbs, but not identical. Per cup, cantaloupe has about 12.7 grams of carbohydrates while watermelon has 11.5 grams. The bigger difference shows up in sugar: cantaloupe contains 12.3 grams of sugar per cup compared to watermelon’s 9.4 grams. So watermelon is slightly lower in both carbs and sugar, though the gap is small enough that it rarely matters for most people’s diets.
Compared to higher-carb fruits like bananas (27 grams per medium banana) or mangoes (25 grams per cup), cantaloupe is a noticeably lighter option. It sits in a similar range to strawberries and peaches.
Glycemic Index
Cantaloupe has a glycemic index of 54, which falls into the low-to-moderate range. Foods below 55 are generally considered low GI, meaning they cause a slower, more gradual rise in blood sugar rather than a sharp spike. The high water content of cantaloupe (about 90% water) helps explain why its glycemic impact stays moderate despite most of its carbs coming from sugar. You’re getting a relatively diluted amount of sugar per bite compared to denser fruits like grapes or cherries.
What Else You Get With Those Carbs
Cantaloupe packs a lot of nutrition into its 13 grams of carbs. A single cup delivers a significant percentage of your daily needs for both vitamin A and vitamin C. The orange flesh gets its color from beta-carotene, which your body converts into vitamin A for eye health and immune function. It also provides potassium, which supports blood pressure regulation.
The fiber content at 1.4 grams per cup isn’t especially high compared to fruits like raspberries or pears, but combined with cantaloupe’s high water content, it still supports digestion. That water content also makes cantaloupe a useful hydration source, especially in warmer months when it’s in peak season.