How many carbs are in corn?
Corn has 16.8 g of total carbs per 1 ear (90 g) — about 15 g net carbs after 1.8 g of fiber. That's 18.7 g of carbs per 100 g, roughly 6% of the 275 g Daily Value.
USDA FoodData Central · raw · FDC 169998
Carbs by portion
| Portion | Total carbs | Net carbs | Fiber | Sugar | Calories |
|---|---|---|---|---|---|
| 1 ear (90 g) | 16.8 g | 15 g | 1.8 g | 5.7 g | 77 |
| 100 g | 18.7 g | 16.7 g | 2 g | 6.3 g | 86 |
| 1 oz (28 g) | 5.3 g | 4.7 g | 0.6 g | 1.8 g | 24 |
Net carbs = total carbs − fiber (the carbs that raise blood sugar, used in keto/low-carb tracking). Values computed from USDA per-100 g data (FDC 169998, SR Legacy). raw.
Corn looks like a vegetable and eats like a starch — and the carb count tells you why. A realistic serving — 1 medium ear of sweet corn (90 g) — carries about 17 g of total carbohydrate, which is 18.7 g per 100 g. Subtract the 1.8 g of fiber and you land at roughly 15 g of net carbs per ear. That’s a side-dish number, not a salad-vegetable one, and the twist is that most of it is starch, not the sugar the name “sweet corn” suggests.
Starch, not sugar — why corn is a carb side
Net carbs are total carbs minus fiber, and corn has only modest fiber to subtract, so its ~15 g net sits close to its total. But the more important detail is the type of carbohydrate. Of the ~17 g in an ear, only about 5.7 g is sugar — the rest is largely starch. Per 100 g that’s 18.7 g carbs, 2 g fiber, 6.3 g sugar, for about 77 calories an ear. That starch-heavy profile is exactly why corn sits next to rice and potato on the plate rather than alongside leafy greens. A full cup of kernels climbs to roughly 24 g net carbs — genuinely a starch portion.
What this means for keto and low-carb
For keto, corn is a no. At ~15 g net carbs an ear, it would eat most of a strict 20 g daily budget, and its starchy nature means it spikes blood sugar more like a grain than a green vegetable. On low-carb plans generally, corn is best treated as the carb of the meal — if you’re having corn, you’re probably not also having rice or bread. That’s not a knock on corn; it brings fiber, energy, and eye-health antioxidants like lutein. It just belongs in the starch column, counted accordingly.
Corn actually carries a bit more protein than most vegetables, too. For that side of the picture, see protein in corn. And for canned or creamed corn, read the label’s carb and fiber lines, since added sugar and sauces push the numbers up.
Frequently Asked Questions
How many carbs are in an ear of corn?
About 17 g of total carbohydrate in one medium ear of sweet corn (90 g), which is 18.7 g per 100 g (USDA FDC 169998). With about 1.8 g of fiber per ear, the net carbs come out to roughly 15 g — and most of that is starch, not sugar.
What are the net carbs in corn?
Roughly 15 g net carbs per ear — total carbs (~17 g) minus the ~1.8 g of fiber. Corn has only a little fiber for its carb load, so net carbs stay close to total. The key point is what those carbs are: predominantly starch, which is why corn eats like a side dish, not a salad vegetable.
Is corn's carbohydrate mostly sugar or starch?
Mostly starch. An ear has about 5.7 g of sugar but ~17 g of total carbs, so the majority is starch rather than sugar — even though sweet corn tastes sweet. That starch is exactly why corn belongs in the same plate slot as rice or potato.
Is corn keto or low-carb?
No. At ~15 g net carbs per ear, corn would use most of a strict 20 g keto budget, and it's starchy enough that it doesn't fit low-carb plans well in normal portions. Corn is a starchy vegetable — treat it as your carb for the meal, not a keto-friendly veg like broccoli or zucchini.
How many carbs are in a cup of corn?
A cup of corn kernels is about 145 g, so roughly 27 g of total carbs and around 24 g net carbs (after ~2.9 g fiber). A full cup is a substantial carbohydrate serving — closer to a portion of rice than to a typical vegetable side.
When was this data last verified?
2026-06-04, against USDA FoodData Central FDC 169998 (Corn, sweet, yellow, raw; SR Legacy). We re-verify reference pages periodically and update when USDA revises the entry.
Whole-food values are USDA reference data, not a Labelgrade (that score is for branded packaged products). See our methodology and the macro calculator to turn this into a daily target.