Converter
Why cornstarch needs its own conversion
Cornstarch weighs about 112g per cup — quite light and airy compared to many kitchen staples. Derived from King Arthur 1/4 cup = 28 g. Note: UK 'cornflour' = US cornstarch. A cup is a unit of volume, so ingredients this different in density can't share one generic conversion factor — using a single "1 cup = X g" rule for everything will be wrong for at least some of what you cook.
Common measurement mistakes
- Using a generic cup-to-gram factor for every ingredient — cornstarch does not weigh the same per cup as most other ingredients.
- Measurement note: Derived from King Arthur 1/4 cup = 28 g. Note: UK 'cornflour' = US cornstarch.
- Confusing weight ounces with fluid ounces when a recipe lists "oz" — they are not interchangeable.
Frequently asked questions
How many grams are in a cup of cornstarch?
About 112g, derived from King Arthur 1/4 cup = 28 g. Note: UK 'cornflour' = US cornstarch.
Does this conversion work for every brand or variety of cornstarch?
It’s a close approximation based on King Arthur Baking. Minor variations in moisture, grain, or brand can shift the exact weight slightly, but this figure works well for everyday cooking and baking.