Starch Conversion

How Many Grams in a Cup of Cornstarch?

A cup of cornstarch weighs about 128 grams. Here is the complete cup-to-gram and gram-to-cup conversion table, plus the answer to common volume-to-weight questions for cornstarch.

1 Cup
128g
grams
1 Tablespoon
8g
grams
1 Teaspoon
2.7g
grams

Volume to Grams — Cornstarch

Quick reference for the most common amounts. Numbers rounded to the nearest gram.

CupsGrams
1/4 cup32 g
1/3 cup42.7 g
1/2 cup64 g
2/3 cup85.3 g
3/4 cup96 g
1 cup128 g
1 1/2 cups192 g
2 cups256 g
3 cups384 g
4 cups512 g
TablespoonsGrams
1 tsp2.7 g
1 tbsp8 g
2 tbsp16 g
3 tbsp24 g
4 tbsp32 g
6 tbsp48 g
8 tbsp64 g
12 tbsp96 g
16 tbsp128 g

Grams to Cups — Cornstarch

Have a recipe in grams and need cups? Use this reverse table.

GramsCupsTablespoons
25 g0.195 cups3.13 tbsp
50 g0.391 cups6.25 tbsp
75 g0.586 cups9.38 tbsp
100 g0.781 cups12.5 tbsp
150 g1.17 cups18.8 tbsp
200 g1.56 cups25 tbsp
250 g1.95 cups31.3 tbsp
300 g2.34 cups37.5 tbsp
500 g3.91 cups62.5 tbsp
1000 g7.81 cups125 tbsp

Why does cornstarch weigh what it weighs?

Pure starches like cornstarch and tapioca are extremely fine and pack tightly. A heaping spoonful versus a leveled one can mean a 50% difference in thickening power — the difference between a glossy sauce and a gummy one. Always level when measuring by volume, or weigh for true precision.

For cornstarch specifically, 1 cup weighs 128g. That is the figure to plug into recipes calling for cup measurements when you want gram precision. ChefVault stores this density (and 118 others) so you never have to look it up twice.

Recipes that originated outside the United States almost always specify weight in grams. Translating these to US cup measurements introduces error in every step. The ChefVault app handles the math automatically — paste a recipe, hit convert, get a clean weight-based version.

Frequently Asked Questions

How many grams are in 1 cup of cornstarch?

1 cup of cornstarch weighs approximately 128 grams.

How many grams in 1 tablespoon of cornstarch?

1 tablespoon of cornstarch weighs approximately 8 grams.

How many grams in 1 teaspoon of cornstarch?

1 teaspoon of cornstarch weighs approximately 2.7 grams.

How many grams are in 1/2 cup of cornstarch?

1/2 cup of cornstarch weighs about 64 grams.

How many grams are in 1/4 cup of cornstarch?

1/4 cup of cornstarch weighs about 32 grams.

How many tablespoons of cornstarch are in 100 grams?

100 grams of cornstarch is about 12.5 tablespoons.

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