Baking
Cake Flour Conversion
Cake Flour weighs 114g per US cup.
| Amount | Grams | Ounces |
|---|---|---|
| 1 cup | 114.0 g | 4.02 oz |
| 1/2 cup | 57.0 g | 2.01 oz |
| 1/4 cup | 28.5 g | 1.01 oz |
| 1 tbsp | 7.1 g | 0.25 oz |
| 1 tsp | 2.4 g | 0.08 oz |
| 100 g | 100.0 g | 3.53 oz |
Need a different amount? Use the full Ingredient Converter tool.
Cake flour is the lightest wheat flour on this site by cup weight — 114 grams, spooned and leveled — a direct result of its low protein content (roughly 7-9%, well under all-purpose flour's 10-12%), milled specifically from soft wheat to minimize gluten formation rather than encourage it.
US cake flour is also typically chlorinated, a processing step (increasingly rare outside large commercial mills but still standard for major retail brands) that weakens the starch structure and slightly acidifies the flour — both of which help a cake batter set into a finer, more tender crumb and hold more sugar and fat without collapsing.
Because real cake flour isn't always on hand, this site's all-purpose-flour substitutes page includes the standard approximation — 1 cup all-purpose flour minus 2 tablespoons, plus 2 tablespoons of cornstarch — which lowers the effective protein percentage closer to cake flour's, though it doesn't replicate the chlorination step exactly.
Cake flour sits at the opposite end of the protein spectrum from bread flour, milled from soft wheat and chlorinated in a process that further weakens gluten formation — its lower 114g-per-cup weight and finer, softer texture are both direct results of that lower protein content, which is exactly why swapping cake flour for all-purpose in a recipe (or vice versa) changes more than just the conversion math; it changes how much structure the batter can build.
A common home substitute — replacing 2 tablespoons of a cup of all-purpose flour with cornstarch — approximates cake flour's lower protein ratio reasonably well in a pinch, though it doesn't replicate the chlorination process that also affects how the flour interacts with sugar and fat in a delicate cake batter.
Boxed cake mixes are formulated around this same lower-protein profile, which is part of why they produce a noticeably more tender crumb than a from-scratch cake made with all-purpose flour.
Frequently asked questions
Why is cake flour so much lighter per cup than all-purpose flour?
It's milled from soft, low-protein wheat and ground extremely fine, and that combination of low protein and fine texture simply packs less mass into the same spooned-and-leveled cup than all-purpose flour's coarser, higher-protein structure.
Is cake flour the same as self-rising flour?
No — cake flour has no leavening added; it's simply a low-protein flour. Self-rising flour is regular flour with baking powder and salt already mixed in — the two solve entirely different baking problems.
Does bleached cake flour perform differently than unbleached?
Yes, slightly — the chlorination (bleaching) process weakens starch and adds a touch of acidity that helps batters set with a finer, more tender crumb; unbleached cake flour still has cake flour's low protein but lacks that specific chemical assist.
Can I substitute cake flour 1:1 for all-purpose flour in any recipe?
Not reliably — cake flour's lower protein produces a much more delicate structure, which works against recipes (like bread or pizza dough) that depend on strong gluten development for their texture.
Why does the cake-flour-from-all-purpose-flour substitute use cornstarch specifically?
Cornstarch dilutes the overall protein percentage of the flour blend without adding any gluten-forming protein of its own, which is exactly the mechanism that makes the substitute work as a real approximation rather than just a texture trick.