A medium ear of sweet corn (roughly 6¾ to 7½ inches long) has about 77 calories. That makes corn one of the lower-calorie starchy vegetables, sitting well below a medium baked potato (around 160 calories) while offering a solid mix of fiber, natural sugars, and B vitamins.
Calories by Serving Size
Ear size matters more than most people realize. A small ear (5½ to 6½ inches) comes in closer to 63 calories, while a large ear can reach 100 or more. If you’re eating corn off the cob at a barbecue, most grocery-store ears fall in the medium range of 75 to 85 calories each.
For kernels cut off the cob or scooped from a can, one cup of raw yellow sweet corn kernels contains about 125 calories and 27 grams of carbohydrates, with roughly 3 grams of fiber and 9 grams of natural sugar. Boiling doesn’t change the calorie count in any meaningful way, though draining canned corn removes some added sodium.
White Corn vs. Yellow Corn
White and yellow sweet corn are nearly identical in calories when you compare equal weights. Per 100 grams raw, white corn has about 86 calories while yellow comes in slightly higher. The real difference is in micronutrients: yellow corn contains significantly more vitamin A and far more of the pigments lutein and zeaxanthin (plant compounds that support eye health). Yellow corn has roughly 934 micrograms of lutein and zeaxanthin per cup compared to just 34 in white corn. If you’re choosing between the two purely for calories, it’s a wash.
Popcorn and Cornmeal
Popcorn is still corn, but the calorie math changes dramatically based on how you prepare it. Three cups of plain, air-popped popcorn contain only about 95 calories, making it a surprisingly light snack. Add oil and seasoning and that same three cups climbs to 140 calories or more. Flavored varieties with chocolate or sugary coatings can hit 215 calories for the same portion.
Cornmeal is a different story entirely. One cup of dry yellow cornmeal packs around 442 calories and nearly 94 grams of carbohydrates. That’s because cornmeal is a concentrated, dried product with almost no water weight. You wouldn’t eat a full cup of dry cornmeal in one sitting, but it’s worth knowing if you’re baking cornbread or making polenta that the base ingredient is calorie-dense.
Carbs and Blood Sugar
Corn sometimes gets a bad reputation as a “starchy” vegetable, but its effect on blood sugar is more moderate than you might expect. A cob of sweet corn has a glycemic index around 62 (out of 100), which falls in the medium range. That’s lower than many common breads and breakfast cereals. The glycemic load, which accounts for the actual amount of carbohydrate in a typical serving, comes to about 15. For context, anything under 10 is considered low and over 20 is high, so a single ear of corn lands squarely in the middle.
The 3 grams of fiber per ear slows digestion enough to blunt a sharp blood sugar spike. Eating corn alongside protein or fat (butter on the cob, corn in a chicken taco) slows absorption further.
How Corn Compares to Other Starches
Gram for gram, sweet corn is less calorie-dense than most grains you’d serve in its place. A cup of cooked brown rice has about 248 calories and 52 grams of carbohydrates, roughly double what you’d get from a cup of corn kernels. White rice is similar. A medium baked potato with skin runs about 160 calories. Sweet corn sits on the lighter end of the starchy side-dish spectrum, which is partly why it works well as both a vegetable and a grain substitute in meals.
Where corn falls short compared to brown rice is protein: a cup of corn kernels provides about 5 grams, while brown rice offers around 6. Neither is a significant protein source on its own, but paired with beans or grilled meat, corn rounds out a meal without adding excessive calories.