Flours & Starches
Convert teaspoons of cornstarch to grams
One teaspoon of cornstarch weighs about 2.5 g, and half a teaspoon comes to roughly 1.25 g. Enter any amount below to convert it, or use the chart further down as a quick reference while you cook.
1 tsp of cornstarch =
2.5 g
- oz
- 0.088
- kg
- 0.0025
- lb
- 0.0055
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
teaspoons to grams chart for cornstarch
Print it, screenshot it, or bookmark this page — these are the amounts recipes ask for most often.
| Teaspoons (US) | Grams | Ounces (weight) | Pounds |
|---|---|---|---|
| 1/4 tsp | 0.625 g | 0.022 oz | 0.0014 lb |
| 1/2 tsp | 1.25 g | 0.044 oz | 0.0028 lb |
| 3/4 tsp | 1.88 g | 0.066 oz | 0.0041 lb |
| 1 tsp | 2.5 g | 0.088 oz | 0.0055 lb |
| 1 1/2 tsp | 3.75 g | 0.132 oz | 0.0083 lb |
| 2 tsp | 5 g | 0.176 oz | 0.011 lb |
| 3 tsp | 7.5 g | 0.265 oz | 0.017 lb |
| 4 tsp | 10 g | 0.353 oz | 0.022 lb |
| 6 tsp | 15 g | 0.529 oz | 0.033 lb |
| 8 tsp | 20 g | 0.705 oz | 0.044 lb |
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 teaspoons figure is converted into millilitres or grams using standard unit sizes (tsp = 4.93 ml).
- 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 grams are in 1 teaspoon of cornstarch?
1 teaspoon of cornstarch is 2.5 g. This is based on a density of 120 g per US cup.
How many grams are in 2 teaspoons of cornstarch?
2 teaspoons of cornstarch is 5 g, and 1.25 g for half a teaspoon.
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.