Grams to Cups

Cornstarch Grams to Cups Converter

Convert cornstarch from grams to cups using ingredient-specific baking measurements.

100 grams of cornstarch ≈

0.78US cups

About ¾ cup

Based on 1 US cup of cornstarch = 128g

Data last verified: August 5, 2026

Convert grams to cups

Precision

100 grams of Cornstarch =

0.78US cups

Approximately ¾ cup

Based on 1 US cup of Cornstarch = 128g

Conversions are approximate and may vary by ingredient brand, packing, humidity, and measuring method.

1 US cup of Cornstarch = 128g

Measured spooned lightly and leveled (dry, unsifted, lumps broken up, based on the US cup / 240 ml)

Cornstarch grams to cups conversion table

GramsCups
10g0.08 cups
15g0.12 cups
20g0.16 cups
25g0.20 cups
30g0.23 cups
40g0.31 cups
50g0.39 cups
75g0.59 cups
100g0.78 cups
125g0.98 cups
150g1.17 cups
200g1.56 cups
250g1.95 cups

Kitchen fraction approximation

32g ≈ ¼ cup
43g ≈ ⅓ cup
64g ≈ ½ cup
85g ≈ ⅔ cup
96g ≈ ¾ cup

Sources & how they compare

SourceReported valueComparable source-cup valueTypeMeasurement methodAdopted hereChecked
USDA FoodData Central — Cornstarch (FDC 169698)FDC ID: 169698128 g/1 source cup (exact volume unknown)128gDirecthousehold cup; packing not specifiedAdopted2026-08-05
King Arthur Baking — Ingredient Weight Chart28 g/1/4 source cup (exact volume unknown)112gDerivedspooned and leveled2026-08-05

A comparable source-cup value only scales a half-cup or tablespoon serving to one source cup. When a source does not state the cup's exact volume, we do not present it as a fixed-milliliter normalization.

Measurement notes

  • Cornstarch compacts easily, so break up lumps before filling the cup.
  • Spoon it in lightly and level once; tapping the cup can make the same volume heavier.
  • In the UK and some other regions, cornflour means cornstarch; elsewhere corn flour can mean finely milled whole corn.

Common mistakes

  • Not measuring cornstarch the recommended way — spooned lightly and leveled — is one of the most common sources of error.
  • Assuming 1 cup of cornstarch equals 240g like water — it is actually 128g per US cup.
  • Packing the powder into the cup instead of spooning it in and leveling.

Related amount conversions

100g Cornstarch ≈ 0.78 cups200g Cornstarch ≈ 1.56 cups250g Cornstarch ≈ 1.95 cups500g Cornstarch ≈ 3.91 cups

Frequently asked questions

How many cups is 100 grams of cornstarch?

100 grams of cornstarch is about 0.78 cups, based on 1 US cup (240 ml) = 128g.

How many grams are in 1 cup of cornstarch?

1 US cup of cornstarch is about 128 grams, measured spooned lightly and leveled.

Does 1 cup of cornstarch weigh the same in a metric cup?

No. A metric cup (250 ml) holds slightly more than a US cup (240 ml), so 1 metric cup of cornstarch is about 133.3g, compared with 128g in a US cup.

What's the best way to measure cornstarch accurately?

For the most accurate result, spooned lightly and leveled, and use a kitchen scale when your recipe calls for a precise weight.

Can I convert cups of cornstarch back to grams?

Yes, use the Cups to Grams tool with cornstarch selected to convert any cup amount back into grams.

Why does cornstarch convert differently from other ingredients?

Grams measure weight and cups measure volume, so the conversion depends on how dense cornstarch is. A cup of cornstarch weighs 128g, while a denser or lighter ingredient weighs a different amount per cup.

Where do these numbers come from?

See how we measure ingredient density and verify each grams-per-cup value.