How many carbs are in corn?
One medium ear of corn has about 22g of carbohydrate and 19g of net carbs. Corn behaves more like a starchy vegetable than a low-carb one.
Carbs by portion
| Portion | Total carbs | Fiber | Net carbs |
|---|---|---|---|
| 1 medium ear (103g) | 21.6g | 2.5g | 19.1g |
| 1 ear small (89g) | 18.7g | 2.1g | 16.5g |
| 1 ear large (118g) | 24.8g | 2.8g | 21.9g |
| 1 cup (149g) | 31.3g | 3.6g | 27.7g |
| 100 grams | 21.0g | 2.4g | 18.6g |
Net carbs
One medium ear of corn has about 19g of net carbs, which is total carbs (22g) minus fiber (2g). Corn's fiber is real but modest, making it higher in net carbs than peas or beans per cup. See the net carbs guide.
Glycemic index of corn
The glycemic index of corn is about 52. Sweet corn has a medium GI. The intact kernel structure slows digestion compared to corn-based processed products like cornflakes (GI 81) or popcorn (GI 65). Corn tortillas and corn chips also have substantially higher GIs than whole corn.
For diabetes
One ear of corn is about 22g of carbs with a medium GI of 52. It is a real carb load but digests more slowly than potatoes or bread. One ear is a reasonable portion for a mixed meal. Canned corn packed in syrup adds 4 to 5g of extra carbs per half cup compared to plain canned or fresh. Creamed corn adds starch and often sugar, pushing per-cup carbs to 30 to 40g. See the diabetes carb-counting guide.
Keto and low carb
One medium ear of corn has about 19g of net carbs, filling a full strict keto day's budget. Corn does not fit keto. Baby corn (used in stir-fry) is much smaller and has about 2g of carbs per piece.
Good to know
Sweet corn sold fresh in the US is a different variety from field corn used for corn syrup, cornmeal, and tortillas. Sweet corn has more sugar and less starch than field corn, which is why the GI of whole sweet corn (52) is meaningfully lower than corn tortillas or cornflakes. Frozen sweet corn without added sugar is nearly identical in carbs to fresh. Hominy (field corn soaked in lye) has a somewhat different carb profile and is used in grits and posole.
Full nutrition (per 100g)
- Calories: 96.0 kcal
- Carbohydrate: 20.98g
- Fiber: 2.4g
- Sugars: 4.54g
- Protein: 3.41g
- Fat: 1.5g
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Get the appFrequently asked questions
How many carbs are in corn?
One medium ear of corn (103g) has about 22g of carbohydrate. One cup of corn kernels (149g) has about 31g of carbs.
Is corn a vegetable or a starch?
Nutritionally, corn is classified as a starchy vegetable, similar to potatoes and peas. It has far more carbs than non-starchy vegetables like broccoli or zucchini.
Is corn keto?
No. One ear has about 19g of net carbs, filling a full keto day's budget.
What is the glycemic index of corn?
Whole sweet corn has a GI of about 52. Processed corn products like cornflakes (81) and popcorn (65) have higher GIs because processing breaks down the kernel structure.
Is canned corn the same carbs as fresh?
Plain canned corn (no added sugar) is nearly identical to fresh. Canned corn in syrup or cream-style corn adds extra sugar and starch.