Flours & Starches
Convert ounces of cornstarch to cups
One ounce of cornstarch weighs about 0.236 cup, and half a ounce comes to roughly 0.118 cup. Enter any amount below to convert it, or use the chart further down as a quick reference while you cook.
1 oz of cornstarch =
0.236 cup
About 1/4 cup in recipe notation
- ml
- 55.9
- tbsp
- 3.78
Cornstarch: 120 g per US cup · FAO / INFOODS density database. Cornstarch compacts in the box. Stir it before measuring or a level cup can weigh 135 g.
Full cornstarch chart →Cornstarch at a glance
Every number on this page comes from a single figure: 120 grams per US cup (FAO / INFOODS density database).
- 1 cup
- 120 g
- 1 tablespoon
- 7.5 g
- 1 teaspoon
- 2.5 g
- 1 cup in ounces
- 4.23 oz
- 100 g in cups
- 0.833 cups
- Density
- 0.51 g/ml
ounces to cups chart for cornstarch
Print it, screenshot it, or bookmark this page — these are the amounts recipes ask for most often.
| Ounces (weight) | Cups (US) | Tablespoons (US) | Millilitres |
|---|---|---|---|
| 0.5 oz | 0.118 cup | 1.89 tbsp | 27.9 ml |
| 1 oz | 0.236 cup | 3.78 tbsp | 55.9 ml |
| 2 oz | 0.472 cup | 7.56 tbsp | 112 ml |
| 3 oz | 0.709 cup | 11.3 tbsp | 168 ml |
| 4 oz | 0.945 cup | 15.1 tbsp | 224 ml |
| 5 oz | 1.18 cup | 18.9 tbsp | 279 ml |
| 6 oz | 1.42 cup | 22.7 tbsp | 335 ml |
| 8 oz | 1.89 cup | 30.2 tbsp | 447 ml |
| 12 oz | 2.83 cup | 45.4 tbsp | 671 ml |
| 16 oz | 3.78 cup | 60.5 tbsp | 894 ml |
How this conversion is calculated
Volume-to-weight conversions are only as good as the density behind them. We treat cornstarch as 120 g per US customary cup, which works out to 0.507 g/ml. From there:
- Your ounces figure is converted into millilitres or grams using standard unit sizes (oz = 28.3 g).
- The density above bridges volume and weight in whichever direction you need.
- The result is rounded the way a cook would round it — to the nearest gram, or to a usable fraction such as 7/8 cups.
Measuring cornstarch accurately
Cornstarch compacts in the box. Stir it before measuring or a level cup can weigh 135 g.
If a recipe matters to you — bread, macarons, anything with a tight hydration or ratio — weigh it. A £10 digital scale removes the single largest source of variation in home baking, and it is faster than washing three measuring cups.
When cups are fine
- Liquids measured in a proper jug, where volume is the honest unit anyway.
- Forgiving savoury cooking: soups, stews, stir-fries, marinades.
- Small amounts of leaveners and spices, as long as you use level spoons.
Frequently asked questions
How many cups are in 1 ounce of cornstarch?
1 ounce of cornstarch is 0.236 cup. This is based on a density of 120 g per US cup.
How many cups are in 2 ounces of cornstarch?
2 ounces of cornstarch is 0.472 cup, and 0.118 cup for half a ounce.
How much is 100 g of cornstarch in cups?
100 g of cornstarch is about 7/8 cups. Weight is always the more reliable measurement, so use a scale when the recipe gives grams.
Why do other sites give a different number for cornstarch?
Cornstarch compacts in the box. Stir it before measuring or a level cup can weigh 135 g.
Do UK and Australian cups give the same result?
No. A US customary cup is 236.6 ml, a metric cup used in Australia and New Zealand is 250 ml, and an old UK imperial cup is 284 ml. Our default is the US cup, but you can pick metric cups in the converter.