Grams to cups for cornstarch
One US cup of cornstarch weighs about 128 g, so 100 g is about 0.78 cups (3/4 cup). Spooned, never packed. Real-world range: 120 to 130 g depending on settling. The calculator and table below use this figure for any amount.
Conversion table
| Grams | Cups | Closest kitchen measure |
|---|---|---|
| 25 g | 0.2 | 1/6 cup |
| 50 g | 0.39 | 3/8 cup |
| 75 g | 0.59 | 5/8 cup |
| 100 g | 0.78 | 3/4 cup |
| 125 g | 0.98 | 1 cups |
| 150 g | 1.17 | 1 cup + 1/6 |
| 200 g | 1.56 | 1 cup + 1/2 |
| 250 g | 1.95 | 2 cups |
| 300 g | 2.34 | 2 cups + 1/3 |
| 400 g | 3.13 | 3 cups + 1/8 |
| 500 g | 3.91 | 3 cups + 7/8 |
How to measure it
Cornstarch weighs about 128 g a cup spooned and levelled, though most recipes only ever ask for a tablespoon or two. One level tablespoon is about 8 g, which is the number that matters for thickening sauces and fruit fillings.
It clumps in humid kitchens, so break lumps before measuring. Cornflour in British recipes means this same product; corn flour in American recipes means finely ground cornmeal, a completely different ingredient that weighs more per cup.
Density source: Government food composition data. Method assumed: Spooned and levelled. Sits between flour and sugar in density.
Questions about cornstarch
Other ingredients
See also: why conversion charts disagree and the full density data.