How many grams are in 1 cup of Cornstarch?
One US cup (240 ml) of cornstarch (cornflour) weighs about 112 grams. A US customary cup (236.6 ml) holds about 110 g, a metric cup (250 ml) about 117 g, and an imperial cup (284.1 ml) about 133 g.
Cups of Cornstarch to grams
One US cup (240 ml) of cornstarch (cornflour) weighs about 112 grams (4 oz), measured spoon and level.
Cornstarch (cornflour in the UK) is a powder fine enough to compress heavily: the same cup can hold 112 g spooned or nearly 130 g compacted. Fortunately recipes rarely need more than a few tablespoons.
Ingredient
112 grams
US cup · cornstarch (cornflour) · spoon and level
More precise value: 112 grams
- Cup standard
- US cup · 240 ml
- Ingredient
- cornstarch (cornflour)
- Method
- spoon and level
- Density
- 0.467 g/ml
- Sources
- King Arthur · USDA FDC
- Reviewed
- 2026-08
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Cornstarch by cup standard
The same volume weighs more in a larger cup. These figures scale the reference weight of 112 g per 240 ml US cup by each cup standard’s exact volume.
| Cups | US cup | US customary cup | Metric cup | Imperial cup |
|---|---|---|---|---|
| ⅛ | 14 g | 14 g | 15 g | 17 g |
| ¼ | 28 g | 28 g | 29 g | 33 g |
| ⅓ | 37 g | 37 g | 39 g | 44 g |
| ½ | 56 g | 55 g | 58 g | 66 g |
| ⅔ | 75 g | 74 g | 78 g | 88 g |
| ¾ | 84 g | 83 g | 88 g | 99 g |
| 1 | 112 g | 110 g | 117 g | 133 g |
| 1½ | 168 g | 166 g | 175 g | 199 g |
| 2 | 224 g | 221 g | 233 g | 265 g |
cornstarch (cornflour), spoon and level. Reviewed 2026-08.
Tablespoons and teaspoons
Spoon measures use the US definitions: 1 tablespoon = 14.79 ml (16 per cup) and 1 teaspoon = 4.93 ml (3 per tablespoon).
| Measure | Grams (g) | Ounces (oz) |
|---|---|---|
| 1 tsp | 2.3 | 0.08 |
| 1 tbsp | 6.9 | 0.24 |
| 2 tbsp | 13.8 | 0.49 |
| 4 tbsp (¼ cup) | 27.6 | 0.97 |
| 8 tbsp (½ cup) | 55.2 | 1.95 |
| 16 tbsp (1 cup) | 110.4 | 3.89 |
How to measure Cornstarch by volume
- Stir the box or tin first, then spoon and level — cornstarch cakes as it sits.
- For sauce-thickening amounts, use level tablespoons: about 7 g each.
- UK “cornflour” is the same product; US “corn flour” (finely ground cornmeal) is not.
Why the weight varies
Cornstarch compacts in the box; a scooped cup can weigh noticeably more than a spooned-and-levelled one.
Thickening power scales directly with weight, so a compacted “cup” of cornstarch can turn a silky sauce into a gel. The cornflour/cornstarch naming trap between US and UK recipes causes more failures than the measuring does.
Which value we publish, and why
We publish 112 g per US cup, scaled from King Arthur’s 28 g per ¼ cup; USDA lists 128 g for a more compacted cup.
Values you may see elsewhere
Sources: King Arthur · USDA FDC . Reference weight verified against King Arthur, USDA FDC. Reviewed 2026-08. Conversions are estimates — ingredient weight varies with packing and brand.
Frequently asked questions
How many grams is 1 tablespoon of Cornstarch?
One US tablespoon (14.79 ml) of cornstarch (cornflour) weighs about 6.9 g, and one teaspoon (4.93 ml) about 2.3 g.
How many ounces is 1 cup of Cornstarch?
One US cup of cornstarch (cornflour) weighs about 4 oz (112 g). Note these are weight ounces — for liquids, don’t confuse them with fluid ounces, which measure volume.