Quick Answer
One US cup of cornstarch weighs about 128 grams. That works out to 8 g per tablespoon and 2.67 g per teaspoon. Scoop and level; do not pack. Weights vary slightly by brand, moisture, and how tightly you pack - for precise baking, a kitchen scale beats volume measures.
Key Facts
- 1 cup cornstarch = 128 g
- 1 tablespoon = 8 g
- 1 teaspoon = 2.67 g
- 1/2 cup = 64 g
- Scoop and level; do not pack.
- Values assume standard US measures (1 cup = 236.59 mL)
Frequently Asked Questions
How many grams in 1 cup of cornstarch?
About 128 grams, scoop-and-level for dry ingredients. Scoop and level; do not pack.
How many grams in a tablespoon of cornstarch?
One US tablespoon (15 mL) of cornstarch is about 8 grams. A teaspoon is 2.67 g.
Why does cornstarch weigh more (or less) than water?
Dry ingredients are weighed by how they pack into the cup volume. Cornstarch has an apparent density of about 0.54 g/mL - lighter than water - depending on particle size and air gaps.
How many cups is 100 g of cornstarch?
100 g ÷ 128 g/cup ≈ 0.78 cups - about a little less than a full cup. The reverse table on this page covers 25-1000 g.
Should I weigh or measure by volume?
Weighing is more accurate - volume measures vary with how you scoop, pack, and level, and brands differ by 5-15%. For cookies and cakes where ratios matter, grams are the professional standard. The tables here convert either direction.