The average sugar content in one large cantaloupe is 64 grams. The average sugar content in a small melon is 35 grams. A large melon also has 2 grams of fat, no cholesterol and 139 milligrams of sodium.
A large cantaloupe has 72 grams of total carbohydrates, including the sugar and 7 grams of dietary fiber. It also has 7 grams of protein. Cantaloupe is rich in vitamin A and provides 551 percent of its daily value. The fruit is rich in carotenoids, which give the flesh its pale orange color and are vitamin A precursors. A cantaloupe's share of vitamin C provides 498 percent of it daily value. It also contains large amounts of calcium and iron.