A fine starch used to thicken sauces, gravies, and fillings. One US cup weighs about 128g — almost exactly the same weight than a cup of all-purpose flour.
Cornstarch is preselected below — just enter an amount.
The most commonly searched gram amounts, converted to cups automatically.
| Grams | Cups |
|---|---|
| 25g | 0.20 cups≈ ¼ cup |
| 50g | 0.39 cups≈ ⅓ cup |
| 75g | 0.59 cups |
| 100g | 0.78 cups≈ ¾ cup |
| 125g | 0.98 cups |
| 150g | 1.17 cups≈ 1 ¼ cups |
| 200g | 1.56 cups≈ 1 ½ cups |
| 250g | 1.95 cups |
| 300g | 2.34 cups≈ 2 ⅓ cups |
| 500g | 3.91 cups |
| 1000g | 7.81 cups≈ 7 ¾ cups |
A fine starch used to thicken sauces, gravies, and fillings. It's also commonly labeled "corn flour".
Cornstarch belongs to the Baking Essentials group on GramToCup, alongside other ingredients measured the same way in most kitchens. It shows up most often in thickening sauces & gravies, pie fillings, crisping fried coatings. Its density of 128g per US cup is what this calculator uses to convert between grams and cups automatically — no manual lookup required.
Cornstarch is a dry, milled or ground ingredient full of countless tiny air pockets between the particles. That trapped air is why it weighs relatively little for its volume — the exact weight shifts with how finely it's milled and how much it has settled in the container.
A cup of cornstarch is almost exactly the same weight than a cup of all-purpose flour (125g/cup), even though both fill the same 1-cup measuring cup.
Common mistake: Using a random spoon from the drawer instead of a proper measuring spoon — a "heaping" spoonful can be double the intended amount.
Cornstarch is usually measured in small amounts — use a measuring spoon rather than a cup, and level off the top for an accurate amount.
When a recipe needs to be exact, weigh it on a kitchen scale instead of using a measuring cup at all — it removes packing and settling from the equation entirely.
Store cornstarch in a sealed container — humidity is the main reason the same cup can weigh differently from one day to the next.
100g of cornstarch is approximately 0.78 cups, based on a density of 128g per US cup.
1 US cup of cornstarch weighs about 128g. Use the calculator above to convert any other amount instantly.
Yes — "corn flour" is another common name for cornstarch. The density and conversion values on this page apply either way.
Because cups measure volume and grams measure weight. A cup of cornstarch is almost exactly the same weight than a cup of all-purpose flour (125g/cup) because the two ingredients have different densities — see the density explanation above for why.
Cornstarch is usually measured in small amounts — use a measuring spoon rather than a cup, and level off the top for an accurate amount.
They're in the same category, but check the density first: Cocoa powder weighs 86g per cup versus 128g for cornstarch. Substituting by weight (grams) keeps a recipe accurate; substituting cup-for-cup can change the result if the densities differ much.