Ingredient Guide
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Cornstarch ingredient guide →1 ounce of Cornstarch in cups
Also known as corn flour, cornflour.
1 ounce of cornstarch = 0.22 US cups. That's based on a 128 g per cup baseline. Cornstarch is also called corn flour in some recipes. Because cornstarch can shift with brand and measuring style, weighing is usually more accurate than measuring by volume.
Answer
0.22 cups
Based on cornstarch density of 0.54 g/ml
Sources: King Arthur Baking, USDA FoodData Central
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Packages of cornstarch are usually labeled by weight. These are weight ounces converted at 128 g per cup — not fluid ounces.
| Package size | US cups |
|---|---|
| 4 oz | 0.89 cups |
| 8 oz | 1.8 cups |
| 12 oz | 2.7 cups |
| 16 oz | 3.6 cups |
| 24 oz | 5.3 cups |
| 32 oz | 7.1 cups |
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Cornstarch substitutions
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Cornstarch substitute for cookies
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Cornstarch substitute for cookies →Quick Reference Table
| ounces | cups |
|---|---|
| 1 ounces | 0.22 cups |
| 2 ounces | 0.44 cups |
| 4 ounces | 0.89 cups |
| 8 ounces | 1.8 cups |
| 16 ounces | 3.6 cups |
Figures use the US cup (236.6 ml).
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Ingredient-specific, density-based conversions for baking
1 ounces of Cornstarch equals 0.22 cups
Ingredient-specific · density-based
Cup size
Based on us cup (236.6 ml) · density data from baking references and our own measurements.Advertisement
What the sources say cornstarch weighs
Published values, quoted at the exact measure each source lists. Sources round differently and assume different fill techniques — which is why they rarely agree to the gram.
| Source | Listed measure | Weight |
|---|---|---|
| USDA FoodData Central | 1 cup | 128 g |
| King Arthur Baking | 1/4 cup | 28 g |
CupOrGram standardizes on 128 g per cup (8 g per tablespoon, 3 g per teaspoon) and uses that single value on every page — how we reconcile the sources.
Why this conversion varies
Cornstarch can vary by brand and measuring style.
- Cornstarch may settle, compress, or pour differently based on handling.
- cornstarch can shift with temperature and ingredient texture.
- This page uses a consistent 128 g per cup baseline for repeatable conversions.
Why this conversion matters
Cornstarch can behave differently by brand and handling. Converting cornstarch with a consistent baseline gives you a more dependable starting point for scaling recipes.
Practical baking use
Pure starch extracted from corn. Primary use as a thickener and tenderiser. Use this conversion as a practical starting point for scaling recipes with cornstarch.
- If consistency matters, verify with a small test batch first.
- Use weight-based measurements when precision is critical.
FAQ
How much is 1 ounce of cornstarch in US cups?
1 ounce of cornstarch is 0.22 US cups using a 128 g per cup baseline.
Is 8 oz of cornstarch the same as 1 cup?
1.8 cups — 8 oz by weight of cornstarch is not 1 US cup. A cup of cornstarch weighs 128 g (4.5 oz). Ounces on this page are weight, not fluid ounces — the "8 oz = 1 cup" rule only holds for water-like liquids.
Is it better to weigh cornstarch for baking?
Usually yes. Weight-based measuring reduces shifts from brand and measuring style, so your results are more repeatable.
Related links for Cornstarch
Recipe Context for Cornstarch
For chemical leavening: small weight changes alter rise and browning.
For quick breads: over-leavening can cause collapse after oven spring.
For cookies: balance leavening with acid source for predictable spread.
Common Pitfalls
- Switching brands without re-checking weight can change texture and bake time.
- Using volume-only measurements for dense ingredients can overshoot recipe targets.
- Expired leaveners can underperform even when measured correctly.
Brand Variance Example
Baseline on this page: 1 cup cornstarch = 128g. Real-world range can shift by about 6% because fine powders and leaveners settle during storage, changing cup density.
Example for 2 cups: baseline 256g, common range 240g-272g. If your bake is texture-sensitive, start with the lower bound and adjust after a test batch.
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