The short answer: 1 cup of cornmeal is 236.6 ml and weighs 138 g (King Arthur Baking, spooned and levelled). The volume never changes — a US cup is always 236.6 ml, whatever is in it — but the weight is specific to cornmeal, because every ingredient has its own density. That is the difference between volume and weight, and it is the reason a cup of cornmeal and a cup of another flour can weigh very different amounts.
All weights in this guide are approximate. Cornmeal is ground dried corn, and its weight per cup, 138 g, reflects how densely the coarse granules pack. It gives cornbread its crumbly texture, polenta its body, and fried food its crunch, and it is one of the few flours where the grind matters as much as the weight: fine cornmeal behaves almost like flour, coarse cornmeal gives a gritty, rustic texture, and the two are not interchangeable cup for cup. If the recipe matters — a cake for a celebration, a loaf you have been planning all week — verify with a kitchen scale: weigh 138 g of cornmeal into the bowl instead of measuring a cup, and the question of how you filled the cup disappears entirely.
Cups to millilitres table for cornmeal
| Cups | Millilitres | Grams (cornmeal) |
|---|---|---|
| ¼ cup | 59.1 ml | 34.5 g |
| ⅓ cup | 78.9 ml | 46 g |
| ½ cup | 118.3 ml | 69 g |
| ⅔ cup | 157.7 ml | 92 g |
| ¾ cup | 177.4 ml | 103.5 g |
| 1 cup | 236.6 ml | 138 g |
| 2 cups | 473.2 ml | 276 g |
| 3 cups | 709.8 ml | 414 g |
| 4 cups | 946.4 ml | 552 g |
Read the table in two directions. The millilitres column is the same for every ingredient on this site, because 1 US cup is 236.6 ml by definition: a quarter cup is 59.1 ml, half a cup is 118.3 ml, and 4 cups is 946.4 ml, which is just under a litre. The grams column is specific to cornmeal: it is the millilitres column multiplied by this ingredient's density, so 138 g per cup becomes 69 g for half a cup, 276 g for two cups, and 552 g for four cups. A tablespoon of cornmeal weighs about 8.6 g and a teaspoon about 2.9 g, because there are 16 tablespoons in a cup.
Worked examples
A cake that needs 2 cups of cornmeal. Two cups is 473.2 ml and 276 g. If the recipe was written in grams, that is the number to weigh; if it was written in cups, spoon the cornmeal into the cup and level it off, twice, and do not scoop. Two scooped cups can weigh 20–40 g more than two spooned-and-levelled cups, and in a cake that much extra flour makes a dry, heavy crumb.
A recipe that needs 1/3 cup of cornmeal. A third of a cup is 78.9 ml and 46 g — a small amount, and small amounts are where cups are at their worst. A third-cup measure is worth owning, but weighing 46 g on a scale is more accurate, and for anything under a quarter cup, the tablespoons to grams converter is a better tool than a cup measure at all.
Scaling a recipe that uses cornmeal. If you double a recipe that calls for 1 1/2 cups of cornmeal, you need 3 cups, which is 709.8 ml and 414 g. The volume doubles exactly, and so does the weight — but if the recipe also has leavening, that does not double: the recipe scaler explains why baking powder and yeast scale by less than the full factor. Use the cups to grams converter to check the weight for any amount, and the ingredient density lookup to compare cornmeal with the other 119 ingredients in the table.
How to measure cornmeal, and where the number comes from
The weight of 138 g per cup comes from King Arthur Baking, measured spooned and levelled. The method is the whole story: spoon the cornmeal into the cup with a spoon until it is heaped, then level it off with the back of a knife. Do not scoop the cup through the bag, and do not tap the cup to settle it, because both pack the cornmeal down and add weight. A scooped cup of flour can weigh 20 g more than a spooned-and-levelled one, which is enough to change a cake.
This matters because cornmeal is used for cornbread, polenta, muffins and breading. A recipe written in cups was almost certainly tested with spooned-and-levelled measures, so 138 g is the right starting point — but the only way to be sure is to weigh it. If your baking has ever come out dry, heavy or dense for no obvious reason, the cup is the first suspect, and a kitchen scale is the fix. The ingredient density lookup shows the full table of 120 ingredients with their sources, so you can check any ingredient the same way.
When this conversion matters
It matters most in baking, where cornmeal is a structural ingredient rather than a seasoning. In a cake or a loaf, the ratio of flour to liquid to fat decides whether the crumb is tender or tough, moist or dry, and a 10% error in the flour is a 10% error in that ratio. In a sauce or a batter where cornmeal is a thickener, the same error is less important, because you can adjust the liquid until the texture looks right. The rule of thumb is simple: if the recipe depends on the flour for its structure, weigh it; if the flour is a minor ingredient you can adjust by eye, a cup is fine.
It also matters when you are following a recipe from another country. A US cup is 236.6 ml, a metric cup is 250 ml, and an imperial cup is 284 ml, so a recipe that says 1 cup without saying which cup can be off by 20% before you even start. This page uses the US cup throughout, and the cups to millilitres converter will convert between cup systems if your recipe uses a different one. When in doubt, convert the recipe to grams once, write the grams on the recipe card, and never measure that ingredient by volume again.
Common mistakes
The most common mistake is scooping instead of spooning and levelling. It feels faster, and it is, but it packs cornmeal into the cup and adds 15–25 g per cup, which is enough to make a cake dry. The second mistake is using a liquid measuring jug for a dry ingredient: the meniscus, the spout and the wide top all make it hard to level accurately, so use a dry measuring cup with a flat rim. The third mistake is assuming all flours weigh the same — a cup of cornmeal is 138 g, but a cup of all-purpose flour is 120 g and a cup of semolina is 163 g, so swapping flours cup for cup changes the recipe. The fourth is measuring over the mixing bowl, so a spill goes into the batter instead of back into the bag; measure over the bag or the sink, and level off before you tip it in.
Storage
Airtight container, cool and dry; refrigerate whole-grain cornmeal. Store cornmeal away from strong smells, because it absorbs them, and keep it dry: damp flour clumps, and damp flour also weighs more per cup, which quietly changes every conversion on this page. If you buy cornmeal in bulk, decant it into an airtight container and keep the original bag's date on the lid, so you know how old it is.
Frequently asked questions
How many millilitres is 1 cup of cornmeal?
236.6 ml. A US cup is 236.6 ml for every ingredient, because millilitres measure volume, and the volume of a cup does not depend on what is in it. What changes between ingredients is the weight: 1 cup of cornmeal weighs 138 g, while other flours weigh anything from 85 g to 163 g per cup. If a recipe gives millilitres, use the volume; if it gives grams, use the weight for this specific ingredient.
How many grams is 1 cup of cornmeal?
138 g, spooned and levelled, according to King Arthur Baking. That is an approximate figure: the true weight varies a little with humidity, brand and how the cornmeal was stored, so verify with a kitchen scale when the recipe matters. A tablespoon of cornmeal is about 8.6 g and a teaspoon about 2.9 g, which is useful for small amounts where a cup measure is too blunt.
Is 1 cup of cornmeal the same as 1 cup of all-purpose flour?
No — not by weight, and often not by behaviour either. One cup of all-purpose flour weighs 120 g, while one cup of cornmeal weighs 138 g, so a cup-for-cup swap changes the amount of flour in the recipe by 18 g per cup. The two also behave differently: cornmeal is used for cornbread, polenta, muffins and breading. If you substitute, weigh the cornmeal rather than measuring it by volume, and expect a different texture.
Should I use a cup or a scale for cornmeal?
A scale, whenever the recipe matters. Cups are convenient, and they are fine for everyday cooking, but a cup of cornmeal can vary by 20 g or more depending on how you fill it, and that variation is enough to change a cake. A scale removes the method entirely: 138 g is 138 g, however you pour it. If you do use a cup, spoon and level, use a dry measuring cup, and measure over the bag rather than over the bowl.
How do I convert cornmeal from cups to grams for other amounts?
Multiply the number of cups by 138 g. Half a cup is 69 g, two cups is 276 g, and three cups is 414 g — the full table is at the top of this page. For amounts that are not in the table, the cups to grams converter will work them out, and the ingredient density lookup shows the same figure for all 120 ingredients in the database.
Does the weight of cornmeal change if it is sifted or packed?
Yes, and this is why the method is stated on every figure. Sifting aerates cornmeal and makes a cup lighter, packing makes it heavier, and the difference can be 20 g or more per cup. The 138 g figure on this page is for cornmeal spooned and levelled, not sifted and not packed. If your recipe says sifted, sift it first and then measure, or better, weigh it: sifted cornmeal weighed at 138 g per cup would be too much, so follow the recipe's method and the weight together.