Cornstarch: Grams to Cups
1 cup of cornstarch = 128 grams
One US cup of cornstarch weighs 128 grams. One 250 ml metric cup — the one used in the UK, Australia, New Zealand and Canada — holds 135 grams. To convert any weight, divide the grams by the figure for your cup.
Cornstarch weighs 128 g per cup on USDA FoodData Central; King Arthur Baking lists 28 g per ¼ cup (112 g per cup). Recipes rarely use more than a few tablespoons — one tablespoon is about 8 g.
Where the 128 g figure comes from
- USDA FoodData Central: 1 cup of “Cornstarch” = 128 g (FDC ID 169698)
- King Arthur Baking ingredient weight chart: Cornstarch, 1/4 cup = 28 g (about 112 g per cup) (chart)
This site uses 128 g per US cup of cornstarch, spooned and levelled. References checked September 2026.
How many cups is X grams of cornstarch?
| Grams | US cups | Metric cups | Tablespoons | Ounces |
|---|---|---|---|---|
| 25 g cornstarch | ¼ | ⅛ | 3.13 | 0.88 |
| 50 g cornstarch | ⅜ | ⅜ | 6.25 | 1.76 |
| 75 g cornstarch | ⅝ | ½ | 9.38 | 2.65 |
| 100 g cornstarch | ¾ | ¾ | 12.5 | 3.53 |
| 110 g cornstarch | ⅞ | 0.81 | 13.75 | 3.88 |
| 120 g cornstarch | 0.94 | ⅞ | 15 | 4.23 |
| 125 g cornstarch | 1 | ⅞ | 15.63 | 4.41 |
| 130 g cornstarch | 1 | 1 | 16.25 | 4.59 |
| 140 g cornstarch | 1⅛ | 1 | 17.5 | 4.94 |
| 150 g cornstarch | 1⅛ | 1⅛ | 18.75 | 5.29 |
| 170 g cornstarch | 1⅓ | 1¼ | 21.25 | 6.00 |
| 175 g cornstarch | 1⅜ | 1⅓ | 21.88 | 6.17 |
| 200 g cornstarch | 1.56 | 1½ | 25 | 7.05 |
| 225 g cornstarch | 1¾ | 1⅔ | 28.13 | 7.94 |
| 240 g cornstarch | 1⅞ | 1¾ | 30 | 8.47 |
| 250 g cornstarch | 1.95 | 1⅞ | 31.25 | 8.82 |
| 275 g cornstarch | 2⅛ | 2 | 34.38 | 9.70 |
| 300 g cornstarch | 2⅓ | 2¼ | 37.5 | 10.58 |
| 350 g cornstarch | 2¾ | 2⅝ | 43.75 | 12.35 |
| 400 g cornstarch | 3⅛ | 2.96 | 50 | 14.11 |
| 450 g cornstarch | 3½ | 3⅓ | 56.25 | 15.87 |
| 500 g cornstarch | 3⅞ | 3⅔ | 62.5 | 17.64 |
How to measure cornstarch accurately
The 128 g figure assumes the spooned-and-levelled method: spoon the cornstarch into a dry measuring cup and sweep the top flat with a straight edge. Scooping the cup through the bag compacts it and gives a heavier cup.
- 1 US cup of cornstarch = 128 g
- 1 metric cup (250 ml) of cornstarch = 135 g
- ¾ cup = 96 g
- ½ cup = 64 g
- ⅓ cup = 43 g
- ¼ cup = 32 g
- 1 tablespoon = 8.0 g
Frequently asked questions
How many cups is 100 grams of cornstarch?
100 grams of cornstarch is about ¾ US cups, based on 128 g per cup, or ¾ metric cups.
How many grams in a cup of cornstarch?
One US cup of cornstarch weighs 128 grams. A 250 ml metric cup holds 135 grams.
How many cups is 250 grams of cornstarch?
250 grams of cornstarch is about 1.95 US cups, or 1⅞ metric cups.
Does a UK cup of cornstarch weigh the same as a US cup?
No. A UK, Australian or Canadian metric cup is 250 ml against the US 236.6 ml, so it holds about 5.7% more — 135 g of cornstarch rather than 128 g.
How many tablespoons is 100 grams of cornstarch?
100 grams of cornstarch is about 12.5 tablespoons.
More flours conversions: Arrowroot Powder grams to cups and Coconut Flour grams to cups.