UrbiTools

Cornstarch Grams to Cups Converter

Convert cornstarch grams to cups and back at a typical 128 g per US cup — with one tap. Everything runs instantly in your browser; nothing is uploaded.

Convert cornstarch grams ⇄ cups

Typical 128 g per US cup; lightly spooned cornstarch can weigh about 120 g.
Presets
0.7813 cups
100 g = 0.7813 cups at 128 g per US cup · about 12.5 tablespoons

Formula: cups = grams ÷ grams-per-cup. Cornstarch settles and packs, so weigh it when a sauce depends on it.

Approximate weights: cornstarch weights per cup vary with packing and brand — 128 g is a typical US-cup value. For thickening, weigh with a scale when it matters.

How the cornstarch conversion works

The converter applies cups = grams ÷ grams-per-cup. A US cup of cornstarch weighs about 128 g — lighter than flour by the cup because the starch is so fine it traps air, which is also why it settles and packs: the same cup can weigh 120 g spooned lightly or more once tapped down. That is why this page works from an adjustable grams-per-cup figure rather than a single fixed number.

Worked example: a sauce calling for 64 g of cornstarch needs 64 ÷ 128 = ½ cup — or 8 tablespoons. A recipe calling for 100 g needs 100 ÷ 128 = 0.78 cups, about ¾ cup plus a tablespoon.

Quick reference

  • ¼ cup cornstarch — 32 g
  • ⅓ cup cornstarch — 43 g
  • ½ cup cornstarch — 64 g
  • ¾ cup cornstarch — 96 g
  • 1 cup cornstarch — 128 g
  • 1 tablespoon cornstarch — 8 g

This is the dedicated cornstarch page of our kitchen cluster — see the flour grams to cups converter for the ingredient cornstarch most often replaces, and the cups to grams cheat sheet for the full table.

cornstarch questions

How many grams is a cup of cornstarch?
About 128 g for a US cup, the typical value this converter uses. Lightly spooned cornstarch can weigh about 120 g a cup, and firmly packed more — which is why the converter lets you adjust the grams-per-cup figure.
How many cups is 100 g of cornstarch?
About 0.78 cups (100 ÷ 128) — roughly ¾ cup plus 1 tablespoon. In spoon terms, 100 g is about 12.5 tablespoons.
How many tablespoons is 1 cup of cornstarch?
16 tablespoons per cup, so 1 cup is 128 g and 1 tablespoon is about 8 g. For small amounts, tablespoons are more accurate than fractions of a cup.
Is cornstarch the same as cornflour?
In the US, cornstarch is the fine white thickening starch; in the UK the same product is usually sold as cornflour. (US cornflour, confusingly, is a different, coarser meal.) For this converter, “cornstarch” means the fine starch at about 128 g per cup.
Can I convert cups of cornstarch back to grams?
Yes — switch the direction above. Grams = cups × grams-per-cup, so ½ cup of cornstarch is 0.5 × 128 = 64 g.

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Sources & official guidance

Estimate only — ingredient weights vary by packing, grind, brand and temperature. See our disclaimer.