Cornstarch: Cups to Grams
1 cup of cornstarch weighs about 112 grams. Convert any amount instantly below.
Cornstarch conversion chart
| Cups | Grams | Ounces | Tablespoons |
|---|---|---|---|
| 1/8 cup | 14 g | 0.5 oz | 2 tbsp |
| 1/4 cup | 28 g | 1 oz | 4 tbsp |
| 1/3 cup | 37.3 g | 1.3 oz | 5.3 tbsp |
| 1/2 cup | 56 g | 2 oz | 8 tbsp |
| 2/3 cup | 74.7 g | 2.6 oz | 10.7 tbsp |
| 3/4 cup | 84 g | 3 oz | 12 tbsp |
| 1 cup | 112 g | 4 oz | 16 tbsp |
| 1 1/4 cup | 140 g | 4.9 oz | 20 tbsp |
| 1 1/3 cup | 149.3 g | 5.3 oz | 21.3 tbsp |
| 1 1/2 cup | 168 g | 5.9 oz | 24 tbsp |
| 1 3/4 cup | 196 g | 6.9 oz | 28 tbsp |
| 2 cup | 224 g | 7.9 oz | 32 tbsp |
| 3 cup | 336 g | 11.9 oz | 48 tbsp |
Based on 112 g per US cup. Weights vary with brand and measuring method — for precise baking, use a scale.
Grams to cups: cornstarch
Working backwards from a weight? Here is how common gram amounts of cornstarch convert to cups (at 112 g per cup).
| Grams | Cups | Tablespoons | Ounces |
|---|---|---|---|
| 10 g | 0.09 cups | 1.4 tbsp | 0.4 oz |
| 25 g | 0.22 cups | 3.6 tbsp | 0.9 oz |
| 50 g | 0.45 cups | 7.1 tbsp | 1.8 oz |
| 75 g | 0.67 cups | 10.7 tbsp | 2.6 oz |
| 100 g | 0.89 cups | 14.3 tbsp | 3.5 oz |
| 125 g | 1.12 cups | 17.9 tbsp | 4.4 oz |
| 150 g | 1.34 cups | 21.4 tbsp | 5.3 oz |
| 200 g | 1.79 cups | 28.6 tbsp | 7.1 oz |
| 250 g | 2.23 cups | 35.7 tbsp | 8.8 oz |
| 300 g | 2.68 cups | 42.9 tbsp | 10.6 oz |
| 500 g | 4.46 cups | 71.4 tbsp | 17.6 oz |
Measuring cornstarch accurately
Cornstarch compacts hard in the box, so loosen it and spoon it into the cup rather than dipping. Level without tapping. Even small differences matter when it's a thickener, so for sauces and gravies weighing 112g per cup gives you predictable, lump-free results.
112 g or 128 g? Why the two authorities disagree on a cup of cornstarch
Look cornstarch up in two reference charts and you will get two answers, and neither is a typo. King Arthur Baking's chart lists 1/4 cup at 1 oz (28 g), which is 112 g per cup and the figure this page and its calculator use. USDA's FoodData Central measures the same level cup at 128 g. The difference is how the cup was filled: King Arthur spoons the powder in gently and sweeps it level; USDA's figure is a dipped, settled cup. The US nutrition labels agree with USDA — Argo and Bob's Red Mill both print 1 tablespoon = 8 g, and 8 × 16 is exactly 128.
Cornstarch exaggerates this because it is one of the finest powders in the kitchen. It cakes in the box, settles as it fills, and a cup dipped into the container compresses the last quarter far more than the first. The same thing happens to flour — King Arthur's own test shows a fluffed cup at 120 g and a condensed one at up to 160 g — but cornstarch's gap between methods, about 14%, is smaller and far more consistent. Here is every common measure both ways:
| Measure | Spooned & levelled (King Arthur, 112 g/cup) | Dipped / label method (USDA, 128 g/cup) |
|---|---|---|
| 1 tsp | 2.3 g | 2.7 g |
| 1 tbsp | 7 g | 8 g |
| 2 tbsp | 14 g | 16 g |
| ¼ cup | 28 g | 32 g |
| ⅓ cup | 37.3 g | 42.7 g |
| ½ cup | 56 g | 64 g |
| ⅔ cup | 74.7 g | 85.3 g |
| ¾ cup | 84 g | 96 g |
| 1 cup | 112 g | 128 g |
| 1¼ cups | 140 g | 160 g |
| 1½ cups | 168 g | 192 g |
| 2 cups | 224 g | 256 g |
Left column computed from King Arthur's spoon-and-sweep chart (1/4 cup = 28 g); right column from USDA FoodData Central #169698 (1 cup = 128 g), which is also what Argo and Bob's Red Mill labels print per tablespoon. Ounce equivalents: 1/4 cup = 1 oz spooned.
Which column to use? If the recipe was written in cups on a US baking site, use the spooned figure — that is the convention those recipes were developed with. If you are reconciling a nutrition label or a calorie count, use the USDA figure, because that is the method the label assumes. For thickening it genuinely does not matter: the 1 g between a spooned and a dipped tablespoon is invisible in a pot of gravy, and the cake-flour substitute is 2 tablespoons per cup of flour whichever way you fill the spoon. As a sanity check, any level US cup that weighs between about 110 and 130 g is a legitimate measurement; a 250 mL metric cup (UK, Australia, NZ) lands at 118–135 g. Below 100 g the cup was sifted or under-filled; above 140 g it was packed down or a metric cup was dipped.
Cornflour, corn flour, maizena or cornstarch: which is which
The naming is the trap, not the weight. In the UK, Ireland, Australia, New Zealand, India and South Africa, "cornflour" is cornstarch — Brown & Polson's pack describes itself as "pure fine white corn starch" — so this page applies exactly as written. Those packs give nutrition per 100 g only, with no per-spoon weight, which is why the table above spells out the teaspoon and tablespoon. Maizena, the brand name much of Latin America, Spain, Portugal and South Africa use as a generic word, is cornstarch too.
In the United States, "corn flour" is a different ingredient: finely ground whole corn kernels, germ and bran included — a finer sibling of cornmeal, used for cornbread, tortillas and coatings. It happens to weigh about the same per cup (Bob's Red Mill's label serving of 1/4 cup = 31 g works out to roughly 124 g), but it is yellow, tastes of corn, does not turn clear when cooked and will not thicken a sauce. If a US recipe says corn flour and means it, cornstarch is not a substitute, and vice versa. One further wrinkle for Australian readers: some supermarket "cornflour" there is milled from wheat ("wheaten cornflour"). It measures and thickens the same for practical purposes, but it is not gluten-free — check the pack.
Cornstarch vs arrowroot, tapioca and potato starch per cup
Recipes swap these four thickeners freely, so it helps to know that three of them weigh about the same per cup and one does not:
| Starch | Grams per US cup | Grams per tbsp |
|---|---|---|
| Cornstarch (this page) — spooned | 112 g | 7 g |
| Cornstarch — dipped / label method (USDA) | 128 g | 8 g |
| Arrowroot starch (powder) | 128 g | 8 g |
| Tapioca starch / tapioca flour | 113 g | 7.1 g |
| Potato starch (King Arthur) | 152 g | 9.5 g |
| All-purpose flour (for the thickener swap) | 120 g | 7.5 g |
| US corn flour — whole-kernel, not a starch | 124 g | 7.8 g |
| Cornmeal | 122 g | 7.6 g |
King Arthur Baking chart (cornstarch, tapioca starch, potato starch, all-purpose flour); USDA FoodData Central for the dipped cornstarch cup; arrowroot from the spoon-and-level figure on its own page (King Arthur's chart does not list it); US corn flour from Bob's Red Mill's label serving; cornmeal from its own page. Tablespoon column is the cup weight ÷ 16.
Potato starch is the outlier — King Arthur weighs it at 152 g per cup, a third heavier than cornstarch, and Bob's Red Mill's label serving (1 tbsp = 12 g) implies heavier still, so weigh it rather than converting by cup. Arrowroot and tapioca sit within a few grams of cornstarch, so a recipe's cup measure carries over; what changes is behaviour, not weight — both thicken at a lower temperature than cornstarch, give a glossier, clearer gel, and turn stringy if boiled hard. Swapping cornstarch for flour is the one exchange that is not weight-for-weight or cup-for-cup: the cornstarch to flour converter handles the 1 : 2 volume rule (47% by weight) in both directions. Weighing a whole coating mix — flour, cornstarch, salt, pepper — in one bowl? The recipe weight calculator totals the list.
Frequently asked questions
How many grams is 1 cup of cornstarch?
1 US cup of cornstarch weighs about 112 grams.
How many grams is 3/4 cup of cornstarch?
Three quarters of a US cup of cornstarch is about 84 grams (12 tablespoons).
How many grams is 2/3 cup of cornstarch?
2/3 of a US cup of cornstarch is about 74.7 grams.
How many grams is 1/2 cup of cornstarch?
Half a US cup of cornstarch is about 56 grams — half of the 112 g in a full cup.
How many grams is 1/3 cup of cornstarch?
A third of a US cup of cornstarch is about 37.3 grams.
How many grams is 1/4 cup of cornstarch?
A quarter US cup of cornstarch is about 28 grams (4 tablespoons).
How many grams is 1 tablespoon of cornstarch?
1 tablespoon of cornstarch is about 7 grams (a cup is 16 tablespoons).
How many grams is 1 1/4 cups of cornstarch?
1 1/4 US cups of cornstarch weigh about 140 grams.
How many grams is 1 1/2 cups of cornstarch?
1 1/2 US cups of cornstarch weigh about 168 grams — one full cup (112 g) plus half a cup (56 g).
How many grams is 2 cups of cornstarch?
2 US cups of cornstarch weigh about 224 grams.
How many cups is 100 grams of cornstarch?
100 grams of cornstarch is about 0.89 cups.
How many cups is 250 grams of cornstarch?
250 grams of cornstarch is about 2.23 cups (at 112 g per cup).
How many cups is 500 grams of cornstarch?
500 grams of cornstarch is about 4.46 cups.
Is 1 cup of cornstarch 112 grams or 128 grams?
Both are real measurements of a level US cup — they differ in how the cup was filled. King Arthur's chart spoons cornstarch gently into the cup and sweeps it level: 1/4 cup = 1 oz = 28 g, so 112 g per cup (the figure this page uses). USDA's lab measures a dipped, settled cup at 128 g. Cornstarch is a very fine powder that packs down as it fills, so dipping the cup into the box runs about 14% heavier than spooning. If your recipe comes from a US baking site written in cups, use 112 g; if you are working from a nutrition label, use 128 g.
How many grams is 1 tablespoon of cornstarch on the nutrition label?
8 grams. Argo and Bob's Red Mill both print a serving of 1 tbsp (8 g) — and 8 g × 16 tablespoons is exactly USDA's 128 g cup, because labels use the dipped-spoon method. A spooned tablespoon per King Arthur's chart is about 7 g. For thickening a sauce the difference is invisible; for a recipe given in grams, weigh it.
How many cups is 56 grams of cornstarch?
Half a cup, spooned and levelled. 56 g is 2 oz, and King Arthur's chart puts 1/4 cup of cornstarch at 1 oz (28 g), so 2 oz is 1/2 cup exactly — which is why 56 g turns up so often in recipes converted from ounces. Measured by the label method (8 g per tablespoon) it is 7 tablespoons, or about 0.44 cup.
Is cornflour the same as cornstarch?
In the UK, Ireland, Australia, New Zealand, India and South Africa, yes — "cornflour" is the pure white starch this page is about, and every figure here applies as written (UK packs such as Brown & Polson print no per-spoon weight, so use the table above). In the United States "corn flour" is a different product: finely ground whole corn kernels, more like fine cornmeal. It weighs about the same per cup (Bob's Red Mill's label works out to ~124 g), but it tastes of corn, does not turn clear and will not thicken a sauce.
How much does 1 cup of flour plus 1/2 cup of cornstarch weigh?
About 176 grams — 120 g of all-purpose flour plus 56 g of cornstarch. Add the seasoning a typical crispy-coating or fried-chicken dredge calls for and you are at roughly 184 g: 1 teaspoon of table salt is about 5.7 g and 1 teaspoon of ground black pepper about 2.3 g (USDA). The recipe weight calculator totals any list like this in one go.
Does cornstarch weigh the same as flour per cup?
Nearly, but not quite: a spooned cup of cornstarch is about 112 g against 120 g for all-purpose flour, so cornstarch is about 7% lighter. That matters if you are swapping thickeners by weight — the familiar "1 tablespoon cornstarch replaces 2 tablespoons flour" is a volume rule, and by weight it works out to about 47% as much cornstarch, not 50%.
Do arrowroot, tapioca and potato starch weigh the same as cornstarch?
Arrowroot and tapioca starch do, near enough: about 128 g and 113 g per cup against cornstarch's 112–128 g. Potato starch is the heavy one — King Arthur's chart lists 152 g per cup, and Bob's Red Mill's label (1 tbsp = 12 g) implies heavier still — so weigh it rather than assuming. Volume-for-volume swaps between these starches are a technique question (arrowroot and tapioca thicken at lower temperatures and go stringy if boiled), not a weight one.
How many cups of cornstarch are in a 16 oz box?
About 4.05 cups spooned and levelled, or about 3.54 cups by the dipped, label method — a 16 oz box holds 454 g. Either way, one box is a little over 3½ to 4 cups, which is 57–65 tablespoons of thickener.
Other flours & starches
See the full flours & starches conversion chart →