Convert Cups to Grams: Cornstarch

Convert cups of cornstarch to grams with this complete reference table. 1 cup of cornstarch = 128g (USDA FoodData Central, spooned-and-leveled method). Use the table below for fractions from 1/8 cup up to 4 cups. For precision baking, weight measurements in grams are always more reliable than volume measurements in cups, because cornstarch density can vary by measuring technique.

1 cup
128g
1/2 cup
64g
2 cups
256g

Cornstarch Cups to Grams Table

CupsGrams
1/8 cup16g
1/4 cup32g
1/3 cup42.7g
1/2 cup64g
2/3 cup85.3g
3/4 cup96g
1 cup128g
1 1/4 cups160g
1 1/2 cups192g
2 cups256g
3 cups384g
4 cups512g

Based on USDA FoodData Central data (1 US cup = 240ml = 16 tablespoons = 48 teaspoons). Note: Cornstarch (corn flour in UK) is a fine white powder. 1 cup = 128g. Used as a thickener for sauces and gravies. 1 tablespoon cornstarch = 2 tablespoons all-purpose flour as a thickener.

About Cornstarch Density

The density of cornstarch determines how much it weighs per unit of volume. At 0.533g/ml, 1 US cup (240ml) of cornstarch weighs 128g under USDA standard conditions.

Volume measurements can vary by ±10–20% depending on technique (sifted vs. spooned vs. scooped). For consistent baking results, use a kitchen scale with gram measurements whenever possible. The USDA standard (spooned-and-leveled) is the reference point for all values on this page.

Frequently Asked Questions

How many grams is 1 cup of cornstarch?

1 cup of cornstarch weighs 128 grams (USDA FoodData Central, spooned-and-leveled method, 1 US cup = 240ml).

How many grams is 1/2 cup of cornstarch?

1/2 cup of cornstarch weighs 64 grams.

How many grams is 1/4 cup of cornstarch?

1/4 cup of cornstarch weighs 32 grams.

Does measuring technique affect the weight of cornstarch?

Yes. Sifted cornstarch can weigh up to 20% less than packed or scooped. The USDA standard (spooned-and-leveled) of 128g/cup is the most reliable baseline.

Direct Conversion Pages for Cornstarch

Data source: USDA FoodData Central SR Legacy (FDC ID: 20027). View original USDA record

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