Cake Flour Substitute: Exact Swaps for Any Amount

Updated August 2026 · Baking Resources

For 1 cup of cake flour, measure 1 cup of all-purpose flour, remove 2 tablespoons, and add 2 tablespoons of cornstarch in their place. Sift the two together at least twice, three times if you have the patience, then use it exactly like cake flour in your recipe.

That's it. No other changes to liquid, leavening, or bake time. The result gives you a softer, finer crumb than plain all-purpose, and in most cakes you won't be able to tell it from the boxed stuff.

Converting a whole recipe, or working in grams? Our free substitutions finder scales this for any amount.

Updated August 2026

Flour is just protein, and protein is gluten

Understand this one thing and every flour on the shelf makes sense.

Wheat flour contains two proteins, glutenin and gliadin. Add water and stir, and they link up into gluten, the stretchy network that gives bread its chew and holds a loaf's shape. More protein means more gluten. More gluten means more structure and more chew.

That's the only meaningful difference between most flour types. Not the brand, not the packaging, not the price. The protein percentage.

• Cake flour: about 7 to 9% protein. Milled from soft wheat, ground very fine. Barely any gluten forms, so you get a tender, fine, almost velvety crumb that pulls apart in soft crumbs rather than strands.
• All-purpose: about 10 to 12%. The compromise. Enough gluten for cookies and quick breads, more than a delicate cake wants.
• Bread flour: about 12 to 14%. Hard wheat. Lots of gluten, which is exactly what a loaf needs and exactly what ruins a sponge cake.

Now the cornstarch trick stops being a kitchen folk remedy and becomes obvious.

Cornstarch is pure starch. Zero protein. When you pull 2 tablespoons of all-purpose flour out of a cup and drop 2 tablespoons of cornstarch in, you've removed protein and replaced it with something that contributes none. The protein percentage of the whole cup drops.

Run the numbers. A cup of all-purpose flour is about 120 grams at roughly 11% protein, so 13.2 grams of protein. Take out 2 tablespoons, about 15 grams, and you're left with 105 grams of flour carrying about 11.6 grams of protein. Add 16 grams of cornstarch and the total is 121 grams containing 11.6 grams of protein. That's 9.5% protein.

You started at 11% and landed at 9.5%. That's just above the top of the cake flour range, in pastry-flour territory. It isn't literally identical to a 7.5% cake flour, and anyone who tells you it is hasn't done the math. But it's a real, measurable drop in gluten potential, and in the overwhelming majority of cakes that's enough to give you the softer crumb you were after.

The cake flour substitute formula, step by step

1. Measure 1 cup of all-purpose flour into a bowl. Spoon it in and level it off rather than scooping with the cup, which packs in extra.
2. Remove 2 tablespoons and put them back in the flour bin.
3. Add 2 tablespoons of cornstarch.
4. Sift the two together into a second bowl. Then sift back into the first. Then, ideally, once more.
5. Measure out the amount your recipe needs and proceed as written.

For larger amounts, multiply everything. Two cups means removing 4 tablespoons and adding 4 tablespoons of cornstarch. Four cups means 8 and 8, which is a half cup each way.

You can make a big batch and store it. Mix 3 3/4 cups all-purpose with 1/4 cup cornstarch, sift it three times, and keep it airtight. That's 4 cups of cake flour equivalent ready to go.

Why the sifting is not optional

This is the step people skip, and it's the step that decides whether the substitute works.

Cornstarch is a very fine powder with a lot of static cling. Dumped into flour and stirred with a spoon, it forms small dense clumps that look mixed but aren't. Those clumps survive into the batter.

What you get is a cake with pale, chalky, slightly slippery pockets scattered through the crumb. Starch that never dispersed gelatinizes on its own and tastes exactly like what it is: raw cornstarch. It's an unpleasant, gummy little surprise in an otherwise good cake.

Sifting breaks up the clumps and distributes the starch particle by particle across the flour. Two passes is the working minimum. Three is better.

No sifter? Whisk instead. Put both in a wide bowl and whisk hard for a full 30 seconds, then pour the mixture through a fine mesh strainer into another bowl, then whisk again. That gets you there.

There's a second benefit worth having. Sifting aerates the flour, which is part of what cake flour brings to the table. Real cake flour is milled much finer than all-purpose and behaves lighter in the bowl. Sifting your substitute closes some of that gap.

Flour comparison chart

A word about 00 flour

The double-zero is an Italian grading of grind fineness, not protein. It tells you the flour is milled to a talcum-powder texture, and nothing else.

That trips people up constantly. A bag of 00 pizza flour can run 12.5% protein, which is bread-flour territory. A bag of 00 sold for cakes can be 9%. Two bags labeled the same behave nothing alike. Read the nutrition panel, divide the protein grams by the serving size in grams, and you'll know what you actually bought.

Self-rising flour substitute, in both directions

Self-rising flour is not a different wheat. It's soft-wheat flour with the leavening and salt already blended in, sold mostly for Southern biscuits and quick breads.

To make 1 cup of self-rising flour:

• 1 cup all-purpose flour
• 1 1/2 teaspoons baking powder
• 1/4 teaspoon salt

Whisk them together thoroughly, the same way you would the cornstarch blend. If you want a closer match to a brand like White Lily, use the cake flour substitute above as your base instead of straight all-purpose. Real self-rising flour is milled from soft wheat and sits around 8 to 9% protein.

To use self-rising flour when a recipe calls for all-purpose:

Swap it 1:1, then remove the recipe's own baking powder and salt. This is the part people miss, and it's the one that fails loudly.

Say your muffin recipe calls for 2 cups all-purpose, 3 teaspoons baking powder, and 1/2 teaspoon salt. Two cups of self-rising already contains 3 teaspoons of baking powder and 1/2 teaspoon of salt. Leave the recipe's leavening in and you've doubled it. The muffins rise fast, overshoot, and collapse into dense craters, and they taste metallic and salty on top of it.

Two more things to know. Self-rising flour has a shelf life, because the baking powder in it loses strength. Six months from opening is realistic, and after a year it's noticeably weak. And never use it in a recipe with no leavening called for at all, like a shortbread or a pie crust, unless you want it to puff. For a deeper look at how the leavening side works, see our baking powder substitute guide.

What if you just use all-purpose and change nothing?

Honest answer: often it's fine.

Swap all-purpose straight into a cake recipe that wanted cake flour and you'll get a crumb that's a little denser, a little chewier, and less tender. It'll also be slightly less tall, because the tighter gluten network holds the batter back. Most people eating it wouldn't know anything was different.

Where straight all-purpose is perfectly acceptable: pound cake, carrot cake, banana bread, most bundts, coffee cake, cupcakes with a sturdy frosting, anything with fruit or nuts or heavy spices in it. These recipes have enough going on that a slightly firmer crumb reads as normal.

Where it genuinely is not acceptable: angel food cake, chiffon cake, sponge cake, and delicate white layer cakes. These have no fat or very little of it, and the crumb structure is the entire product. There's nothing else in an angel food cake to hide behind. Use all-purpose and you get a tough, rubbery, noticeably shorter cake, and no amount of careful mixing rescues it.

If a recipe leans on cake flour for texture and you only have all-purpose, do the cornstarch swap. It takes two minutes and it's the difference between a good cake and a fine one.

Two habits soften the blow if you're using straight all-purpose anyway. Mix the batter as little as possible once the flour goes in, since every extra stir develops more gluten. And measure by weight, because an over-scooped cup of all-purpose makes the problem twice as bad.

Bleached vs unbleached cake flour

Most US cake flour is bleached, and unlike bleached all-purpose, this one actually matters.

Chlorine gas treatment does two things. It weakens the proteins, dropping the effective gluten strength further. And it alters the starch granules so they absorb more liquid and gelatinize at a lower temperature.

That second effect is the important one. It lets a batter set into a stable structure earlier in the bake, which is what makes so-called high-ratio cakes possible. A high-ratio cake carries more sugar and more liquid by weight than flour, which is why a classic American layer cake is so moist and so sweet. Without bleached flour, that much sugar and liquid keeps the structure loose too long and the center sinks.

Practical takeaway: if your recipe is a rich, very sweet, very moist American layer cake, bleached cake flour is doing real work. Unbleached cake flour holds less liquid and sets later, and those cakes can dip in the middle. In a leaner sponge or a genoise, unbleached is fine and some bakers prefer the cleaner flavor.

Your homemade cornstarch substitute is unbleached by definition, since all-purpose flour on US shelves is usually unbleached and cornstarch isn't treated at all. In a normal butter cake this is a non-issue. In an aggressively high-ratio recipe, expect a slightly denser and moister result, and don't be shocked by a small dip.

Measuring flour by weight vs volume

Flour is the ingredient most wrecked by the measuring cup. It compresses, it settles in the bag, and it holds air depending on how it was handled.

Scoop a cup straight out of the bag with the measuring cup and you compact it. That cup can weigh 145 to 155 grams. Spoon flour gently into the cup and level it and you get 120 to 125 grams. Same cup, same flour, up to 30 grams apart. In a two-cup cake recipe that's more than half a cup of extra flour, and it will absolutely produce a dry, dense cake.

Cake flour is the one with a real spread, and it's worth knowing why. It's milled finer and often sold pre-sifted, so it packs differently from brand to brand. If your recipe came from a specific brand's website, use that brand's number. If it just says "1 cup cake flour," 120 grams is the safe working figure.

Our ingredient weights chart has the full list, and the grams to cups converter handles metric recipes going the other way.

Worked example: converting a 2 1/4 cup cake flour recipe

A standard yellow layer cake calls for 2 1/4 cups of cake flour. You have all-purpose and cornstarch. Here's the conversion both ways.

By volume:

1. Measure 2 1/4 cups of all-purpose flour, spooned and leveled.
2. Remove 2 tablespoons per cup. That's 2.25 × 2 = 4 1/2 tablespoons to take out. Easiest way to count it: 4 tablespoons plus 1 1/2 teaspoons.
3. Add the same 4 1/2 tablespoons of cornstarch back in. That's 1/4 cup plus 1/2 tablespoon.
4. Sift the whole thing together three times.
5. You now have 2 1/4 cups of cake flour equivalent. Use all of it.

By weight, which is faster and more accurate:

1. 2 1/4 cups of cake flour at 120 g per cup is your target: 270 g.
2. Weigh out 236 g of all-purpose flour. (That's 270 g minus the 4 1/2 tablespoons you'd have removed, at about 7.5 g per tablespoon.)
3. Add 36 g of cornstarch (4 1/2 tablespoons at 8 g each).
4. Total: 272 g, within 1% of target. Sift three times.

Check the protein: 236 g of all-purpose at 11% is about 26 g of protein, spread across 272 g of total mix. That's 9.5%, down from the 11% you started with. That's the whole mechanism, in one number.

One last note on this cake. If it also calls for brown sugar and you're out, that one's just white sugar plus molasses. Our brown sugar substitute guide has the exact ratio.

FAQ

What is the best substitute for cake flour?

All-purpose flour with cornstarch: 1 cup all-purpose minus 2 tablespoons, plus 2 tablespoons of cornstarch, sifted two to three times. It drops the protein content from about 11% to about 9.5%, which produces a noticeably softer crumb. It's the closest match you can build from standard pantry items.

Can I use all-purpose flour instead of cake flour?

Yes, 1:1, and the cake will bake and taste fine. The crumb comes out denser and chewier and the cake sits slightly shorter, because all-purpose forms more gluten. It's a fair trade in a pound cake or a banana bread, and a bad one in angel food, chiffon, or a delicate white layer cake.

How do I make cake flour without cornstarch?

Arrowroot powder or potato starch both work, swapped in at the same 2 tablespoons per cup, since both are protein-free starches. Tapioca starch works too but can leave a slightly chewy edge. If you have no starch at all, use pastry flour if you can get it, or accept all-purpose and mix the batter as little as possible.

Is cake flour the same as self-rising flour?

No. Cake flour is plain low-protein flour with nothing added. Self-rising flour is soft-wheat flour that already contains baking powder and salt. Swapping one for the other without adjusting the recipe's leavening and salt will either flatten your bake or make it rise and collapse.

What is the cake flour equivalent in grams?

About 120 g per cup, though real cake flour ranges from 114 to 120 g depending on brand and how finely it's milled. Use the specific brand's number if your recipe came from one. For the homemade version, 105 g of all-purpose plus 16 g of cornstarch gets you to roughly one cup.

Do I really need to sift the flour and cornstarch?

Yes. Cornstarch clumps and clings, and stirring alone leaves dense pockets that survive into the batter and bake into chalky, gummy spots. Sift twice at minimum. If you have no sifter, whisk hard for 30 seconds and push the mix through a fine mesh strainer.

Can I use cake flour for cookies or bread?

For cookies, yes, and it produces a softer, more cakey, less chewy result. Some people love that in a sugar cookie and dislike it in a chocolate chip cookie. For yeast bread, no. There isn't enough protein to build a gluten network, so the loaf will be squat, crumbly, and unable to hold its shape.

Why is my cake dense even though I used cake flour?

Almost always over-measuring or over-mixing. Scooping flour with the measuring cup can pack in 30 extra grams per cup, and every stir after the flour goes in develops more gluten. Weigh your flour, and stop mixing the second the last streak disappears.

Related guides

• Bread Flour vs All-Purpose for the other end of the protein scale
• Brown Sugar Substitute for the other swap every cake recipe eventually needs
• Baking Powder Substitute for the leavening math behind self-rising flour
• Ingredient Weights Chart for gram weights of every flour type
• Substitutions Finder to look up any swap with exact ratios
• Grams to Cups Converter for metric recipes