Cornstarch: Cups to Grams
One US cup (240 ml) of cornstarch weighs about 128 grams, based on its typical kitchen density. Convert any amount below, or use the reference table for common cup fractions.
1 cup=128 g
Based on cornstarch at 128 g per US cup.
Cornstarch conversion table
| Cups | Grams | Millilitres | Tablespoons | Ounces |
|---|---|---|---|---|
| 1/4 cup | 32 g | 60 ml | 4 tbsp | 1.13 oz |
| 1/3 cup | 42.7 g | 80 ml | 5.33 tbsp | 1.51 oz |
| 1/2 cup | 64 g | 120 ml | 8 tbsp | 2.26 oz |
| 2/3 cup | 85.3 g | 160 ml | 10.7 tbsp | 3.01 oz |
| 3/4 cup | 96 g | 180 ml | 12 tbsp | 3.39 oz |
| 1 cup | 128 g | 240 ml | 16 tbsp | 4.52 oz |
| 1 1/2 cups | 192 g | 360 ml | 24 tbsp | 6.77 oz |
| 2 cups | 256 g | 480 ml | 32 tbsp | 9.03 oz |
| 2 1/2 cups | 320 g | 600 ml | 40 tbsp | 11.3 oz |
| 3 cups | 384 g | 720 ml | 48 tbsp | 13.5 oz |
In grams, 1/4 cup of cornstarch is about 32 g, 1/3 cup is about 43 g, 1/2 cup is about 64 g, 2/3 cup is about 85 g, 3/4 cup is about 96 g, 1 cup is about 128 g, 1 1/2 cups is about 192 g, 2 cups is about 256 g and 3 cups is about 384 g.
A tablespoon of cornstarch is about 8 grams, and a teaspoon is about 2.7 grams.
About measuring cornstarch
Cornstarch, known as cornflour in Britain, is a fine white thickening powder, and one US cup weighs about 128 grams. You rarely use a full cup: it usually appears in tablespoons to thicken sauces, pie fillings and custards. Because a little goes a long way, small measuring errors have an outsized effect on how thick your sauce sets, which is why weighing even small amounts can be worth it when precision matters.
Cornstarch is used in small amounts, so even tablespoon errors change how a sauce sets.
Frequently asked questions
How many grams is 1 cup of cornstarch?
One US cup of cornstarch is about 128 grams. It is a fine, dense powder, heavier per cup than flour or cocoa.
How many grams is a tablespoon of cornstarch?
About 8 grams. Since a cup is around 128 grams and holds 16 tablespoons, each tablespoon is roughly 8 grams.
Is cornstarch the same as cornflour?
In Britain, yes. British cornflour is the same fine thickening starch that North America calls cornstarch, and it weighs the same per cup.