Corn Iron Calculator

Corn is often viewed as a starchy side dish, but it also contributes a small amount of iron — and that amount changes depending on the form you eat. Raw sweet corn, boiled kernels, canned corn, whole-grain cornmeal, corn flour, and popcorn all have different iron densities. This makes it tricky to estimate your intake from memory alone.

This corn iron calculator removes the guesswork. Select a corn product, enter your serving size in grams, ounces, cups, or ears, and instantly see how many milligrams of iron it provides, plus the percentage of your Daily Value. The tool uses common U.S. food-composition values and also shows the step-by-step math behind each result.

It is designed for diet planners, home cooks, and anyone tracking micronutrients or comparing corn-based foods. Use the quick-fill buttons for common servings, or adjust the numbers to match the exact portion on your plate. No matter how you eat corn, this calculator helps you understand its modest but real iron contribution.

🌽 Corn Iron Calculator

Estimate the iron in sweet corn, cornmeal, corn flour, and popcorn. Enter any serving size to see milligrams of iron and percent Daily Value.

Choose corn product

Serving size

Quick servings

Cup and ear weights are approximate; actual results vary with moisture and kernel size.

How to Use This Calculator

Start by selecting the corn product closest to what you are eating. The list includes raw sweet corn, boiled sweet corn, canned and frozen kernels, whole-grain cornmeal, corn flour, and air- or oil-popped popcorn. Enter the amount you plan to eat and choose the matching unit. Grams and ounces work for every product; cups work where a typical cup weight is available; ears work only for whole sweet corn.

Press Calculate iron to see your result in milligrams and as a percentage of the adult Daily Value. Use the quick-fill buttons for common servings like one ear or three cups of popcorn. If your nutrition label gives a different iron number, use that instead of this estimate.

How the Iron Calculation Works

The calculator assigns each corn product an iron density in milligrams per 100 grams. To find the iron in your serving, the amount is first converted to grams using a unit weight, then multiplied by that density and divided by 100.

Formula: Iron (mg) = amount in grams × iron density (mg per 100 g) ÷ 100. For cups or ears, the serving is first converted to grams using an average weight from food-composition databases.

For example, air-popped popcorn has about 2.7 mg of iron per 100 g. Because a cup of air-popped popcorn weighs only about 8.5 g, one cup supplies roughly 0.23 mg. That explains why a large bowl can add up quickly, even though a single cup looks small on a nutrition scale.

Worked Examples

Here are two common comparisons to help you build intuition.

Example 1: Sweet corn on the cob. A medium ear of raw sweet corn has about 90 g of kernels. With an iron density of 0.52 mg per 100 g, the ear supplies 90 × 0.52 ÷ 100 = 0.47 mg of iron. That is roughly 2.6% of the 18 mg Daily Value.

Example 2: Popcorn. Three cups of air-popped popcorn weigh about 24 g. At 2.7 mg per 100 g, the iron comes to 24 × 2.7 ÷ 100 = 0.65 mg, or about 3.6% of the Daily Value. Oil-popped popcorn weighs more per cup, so the same 3 cups deliver slightly more iron by weight: about 0.54 mg.

Reference Table: Iron in Common Corn Products

The values below are rounded from typical USDA FoodData Central entries and are meant for meal planning, not medical diagnosis.

Corn product	Iron (mg / 100 g)	Typical serving	Iron per serving
Sweet corn, raw	0.52	1 medium ear (90 g kernels)	0.47 mg
Sweet corn, boiled	0.45	1/2 cup kernels (82 g)	0.37 mg
Sweet corn, canned, drained	0.36	1/2 cup drained (82 g)	0.30 mg
Sweet corn, frozen, cooked	0.37	1/2 cup (82 g)	0.30 mg
Cornmeal, whole-grain	2.38	1/4 cup dry (30 g)	0.71 mg
Cornmeal, degermed, unenriched	1.17	1/4 cup dry (30 g)	0.35 mg
Corn flour, whole-grain	2.38	1/4 cup (29 g)	0.69 mg
Popcorn, air-popped	2.7	3 cups (24 g)	0.65 mg
Popcorn, oil-popped	1.59	3 cups (34 g)	0.54 mg

Notice that the less moisture a product has, the higher its iron density tends to be. Popcorn and cornmeal pack more iron per 100 g simply because they are dry, but their serving sizes are smaller in weight.

Why Processing Changes the Numbers

Whole-grain corn products keep the bran and germ, which are naturally richer in minerals. Degermed or refined cornmeal removes the germ, along with part of the iron; some commercial products are then enriched to add iron back. If your cornmeal label says enriched, check the nutrition facts panel because the iron number may be higher than the value for unenriched degermed cornmeal.

Moisture is another factor. Boiling or canning adds water, which lowers the amount of iron per 100 g even though the iron in the original kernels does not disappear. That is why raw and frozen sweet corn show slightly higher densities than boiled or canned samples.

Tips for Better Iron Absorption

Corn provides non-heme iron, the plant form, which the body absorbs less efficiently than the heme iron in meat, fish, and poultry. To improve absorption, pair corn dishes with vitamin C-rich foods such as tomatoes, bell peppers, citrus juice, salsa, or broccoli.

Tip: Adding a squeeze of lime or a handful of peppers to corn salsa not only improves flavor, but also helps your body use more of the iron from the corn.

Note: The 18 mg Daily Value reference is a general target for adults. Needs differ during pregnancy, infancy, and in conditions like anemia. This calculator is an educational estimate and is not a substitute for individual medical advice.

If you track other trace minerals in your diet, a similar approach works for other vegetables and grains. For another plant-based iron source, try the Sweet Iron Calculator.

If you are also estimating carbohydrates, the Cornmeal Sugar Calculator can help you compare corn products side by side.