Cornstarch Grams to Cups Converter
Convert cornstarch from grams to cups using ingredient-specific baking measurements.
100 grams of cornstarch ≈ 0.78 US cups
About ¾ cup + 1 ½ teaspoons
Based on 1 US cup of cornstarch = 128g
Convert grams to cups
Enter an amount greater than 0.
100 grams of cornstarch equals
0.78 US cups
¾ cup + 1 ½ tsp
- Tablespoons 12.50 tbsp
- Teaspoons 38 tsp
- Milliliters 187.5 ml
Based on 1 US cup of cornstarch = 128g
Customize grams per cup
Enter a number of grams greater than 0.
Conversions are approximate and may vary by ingredient brand, packing, humidity, and measuring method. Spoons: 15 ml tablespoon, 5 ml teaspoon. Kitchen estimates have up to 10% volume rounding error; very small amounts use a threshold. See Methodology for the policy.
How this conversion is calculated
Adopted reference value
1 US cup of Cornstarch = 128g
Data last verified: 2026-08-05
Cup type
US cup / 240 ml
Measuring method
Dry, unsifted, lumps broken up · spooned lightly and leveled
Cornstarch grams to cups conversion table
| Grams | Cups | tbspTablespoons | tspTeaspoons | ml |
|---|---|---|---|---|
| 10g | 0.08 cups | 1.25 | 3.8 | 18.8 |
| 15g | 0.12 cups | 1.88 | 5.6 | 28.1 |
| 20g | 0.16 cups | 2.50 | 7.5 | 37.5 |
| 25g | 0.20 cups | 3.13 | 9.4 | 46.9 |
| 30g | 0.23 cups | 3.75 | 11 | 56.3 |
| 40g | 0.31 cups | 5 | 15 | 75 |
| 50g | 0.39 cups | 6.25 | 19 | 93.8 |
| 75g | 0.59 cups | 9.38 | 28 | 140.6 |
| 100g | 0.78 cups | 12.50 | 38 | 187.5 |
| 125g | 0.98 cups | 15.63 | 47 | 234.4 |
| 150g | 1.17 cups | 18.75 | 56 | 281.3 |
| 200g | 1.56 cups | 25 | 75 | 375 |
| 250g | 1.95 cups | 31.25 | 94 | 468.8 |
Kitchen fraction approximation
¼ cup
≈ 32g
⅓ cup
≈ 43g
½ cup
≈ 64g
⅔ cup
≈ 85g
¾ cup
≈ 96g
Sources & how they compare
| Source | Reported value | Comparable source-cup value | Type | Method the source states | Adopted here | Checked |
|---|---|---|---|---|---|---|
| USDA FoodData Central — Cornstarch (FDC 169698) FDC ID: 169698 | 128 g per 1 cup (volume not stated) | 128g | Direct | household cup; packing not specified | Adopted | 2026-08-05 |
| King Arthur Baking — Ingredient Weight Chart | 28 g per ¼ cup (volume not stated) | 112g | Derived | not stated (the chart lists weights only) | 2026-08-05 |
Measuring step this site recommends: spooned lightly and leveled.
When sources disagree, follow your recipe: use its gram weights if it gives them, or measure the way its author did. The adopted value is one stated convention, not a correction of the other sources.
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
- Assuming 1 cup of cornstarch equals 240g like water — it is actually 128g per US cup.
- Trading cornstarch for flour cup for cup as if they weighed the same; a cup of cornstarch is a little heavier.
Convert other ingredients in your recipe
Cocoa powder
1 cup = 84g · 100g ≈ 1.19 cups
View conversion →
Powdered sugar
1 cup = 120g · 100g ≈ 0.83 cups
View conversion →
Vegetable oil (soybean)
1 cup = 218g · 100g ≈ 0.46 cups
View conversion →
Olive oil
1 cup = 216g · 100g ≈ 0.46 cups
View conversion →
Each link converts that ingredient with its own cup weight; none of them is a substitute for this one.
Related amount conversions
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 dry, unsifted cornstarch, with any lumps broken up, weighs about 128 grams when spooned lightly into the cup 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?
Break up any lumps, spoon the dry cornstarch lightly into the cup without sifting and level it off. 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 denser or lighter ingredient weighs a different amount per cup.