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Cornstarch:
grams to cups.

Cornstarch weighs 128 g per cup — similar to all-purpose flour but with very different culinary uses. Most cornstarch recipes call for tablespoons or teaspoons rather than cups, making the small-measure conversions particularly useful.

Cornstarch: grams to cups

Approximate cup fractions for common gram amounts. Based on 128 g per cup.

Grams Cups (approx) Decimal
25 g 0.20
50 g ½ 0.39
100 g ¾ 0.78
150 g 1 ⅙ 1.17
200 g 1 ⅔ 1.56
250 g 1 1 1.95
500 g 3 1 3.91

Cornstarch: cups to grams

Based on 128 g per cup.

Volume Grams (g)
1 cup 128 g
¾ cup 96 g
½ cup 64 g
⅓ cup 43 g
¼ cup 32 g
1 tbsp 8 g
1 tsp 3 g

Convert cornstarch instantly

Clumping and why cornstarch measurement matters most at small scales

Cornstarch is used in small quantities as a thickening agent, a coating for stir-fry proteins, and an additive to cake flour substitutes. Because it's so fine, it compresses easily in a measuring spoon — a heaped tablespoon of cornstarch can weigh 10–12 g instead of the standard 8 g, a 50% overcharge. In sauce-making, extra cornstarch doesn't ruin a recipe — it just creates a thicker gel. But in baking, where cornstarch is added to weaken gluten (such as in shortbread), over-measuring cornstarch can produce an unpleasantly chalky texture. Always level spoon measures and use weight when precision matters.

Cornstarch vs cornflour: same thing, different names

In the United States, "cornstarch" refers to the pure white starch extracted from corn kernels. In the UK and Australia, the same product is called "cornflour." Confusingly, "cornmeal" — which is ground whole corn — is sometimes also shortened to "cornflour" in British recipes. The density values are different: cornstarch (128 g/cup) is much lighter and finer than cornmeal (138 g/cup). When converting a British recipe that calls for cornflour in a sauce context, it almost certainly means cornstarch; in a cornbread context, it may mean fine cornmeal.

Frequently asked questions

How many grams is 1 tablespoon of cornstarch?
1 tablespoon of cornstarch (1/16 cup) weighs 8 g (128 g ÷ 16).
How many grams is 2 tablespoons of cornstarch?
2 tablespoons of cornstarch weigh 16 g.
How many cups is 500 g of cornstarch?
500 g ÷ 128 g/cup ≈ 3.9 cups — just under 4 cups.

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