How Many Grams in a Tablespoon of Cornstarch?

There are about 7 grams in a tablespoon of cornstarch, spooned in and leveled. King Arthur Baking lists 1/4 cup of cornstarch at 28 g, which works out to 7 g per tablespoon and about 112 g per cup.

Cornstarch is a thickener, so small differences show up fast. One heavy tablespoon can turn a silky pan sauce into something closer to paste, and one light spoonful can leave a pie filling runny.

Why your tablespoon of cornstarch might weigh more

Cornstarch is a very fine, soft powder. It squeaks when you rub it between your fingers, and it packs down easily. That makes volume measuring unreliable:

• Scooping vs spooning. Dipping the spoon straight into the box presses powder into it. Spooning it in loosely and leveling gives you a lighter, more consistent tablespoon.
• Level vs heaped. A fine powder holds a tall mound, so a heaped tablespoon can carry a lot more than 7 g.
• Settling. A box that's been sitting on a shelf is more compact at the bottom than at the top.
• Humidity. In damp kitchens cornstarch can clump. Clumps fill a spoon unevenly, so break them up before measuring.

That's why you'll see charts that list slightly different weights for the same tablespoon. The gram number on your scale doesn't care how the powder was packed.

How to measure cornstarch for a smooth sauce

Getting the amount right is half of it. The other half is how you add it. Argo, the cornstarch maker, recommends this approach:

1. Weigh the cornstarch, such as 7 g for 1 tbsp or 14 g for 2 tbsp.
2. Stir it gradually into cold liquid until it's completely smooth. Adding it straight to a hot pan makes lumps.
3. Stir the mixture into your sauce or filling and keep stirring.
4. Bring it to a full boil and boil for 1 minute so it thickens properly.

If a sauce comes out too thin, it's tempting to dump in more cornstarch. Instead, make a small second slurry with a weighed amount, so you know exactly how much the recipe really needed and can write it down for next time.

Swapping cornstarch and flour by weight

Argo says cornstarch has about twice the thickening power of flour, so you use half as much. Their example: if a recipe calls for 1/4 cup of flour for thickening, use 2 tablespoons of cornstarch instead.

In grams, those 2 tablespoons of cornstarch weigh about 14 g. Using King Arthur Baking's 120 g per cup of all purpose flour, 1/4 cup of flour is about 30 g. Writing both numbers on your recipe card makes the swap easy either way.

A few other spots where weighing cornstarch helps:

• Fruit pie fillings. Juicy fruit needs more thickener than firm fruit. Weighing lets you fine tune by a few grams from one pie to the next.
• Stir fry sauces. A teaspoon is only about 2.3 g, and that small amount is often all a sauce needs.
• Baking. Some cookie and shortbread recipes mix cornstarch into flour for a softer crumb. Weighing both keeps the blend consistent.

Common cornstarch mistakes

• Scooping from the box. It packs the powder and adds weight. Spoon and level, or weigh.
• Adding it dry to hot liquid. Always mix it into cold liquid first.
• Not boiling long enough. Undercooked cornstarch can leave a sauce thin. Give it the full minute at a boil.
• Swapping it one for one with flour. Use about half as much cornstarch as flour.

A practical tip: cornstarch puffs into a cloud when you tip it out of a spoon onto a scale. A MeasureMate digital measuring spoon scoops and weighs in one step, reading in 0.1 g steps, so you can stir 7 g straight from the spoon into your cold water with no extra dishes.

Quick questions

How many grams is 2 tablespoons of cornstarch?

About 14 g, based on King Arthur Baking's 28 g per 1/4 cup.

How many grams of cornstarch are in a teaspoon?

About 2.3 g for a level teaspoon, since there are 3 teaspoons in a tablespoon.

Can I use flour instead of cornstarch?

Yes, but use about twice as much flour, since cornstarch has roughly double the thickening power according to Argo.

Weights based on the King Arthur Baking ingredient weight chart and Argo cornstarch guidance.