Use cake flour instead of all-purpose flour at 1 cup + 2 tbsp cake flour per cup of all-purpose flour. All-purpose flour and cake flour do similar work in a recipe, but they are not identical, and the ratio is what makes the swap succeed. This guide gives the exact ratio, an equivalence table for every amount you will need, what changes in the finished dish, and when you should not make the swap at all. All ratios on this page come from the CookScale substitution data, and every result is approximate; taste the dish before serving, and adjust the seasoning if the swap changes the flavour.
All-purpose flour to Cake flour: equivalence table
The table below scales the ratio — 1 cup + 2 tbsp cake flour per cup of all-purpose flour — to every amount you will need, from a quarter of a cup up to three cups. Use the row that matches your recipe, and do not guess the scaling in your head, because a small error in the ratio grows with the size of the recipe.
| All-purpose flour | Cake flour |
|---|---|
| 1/4 cup | 1/4 cup + 1/2 tbsp |
| 1/2 cup | 1/2 cup + 1 tbsp |
| 1 cup | 1 cup + 2 tbsp |
| 2 cups | 2 cups + 4 tbsp (1/4 cup) |
| 3 cups | 3 cups + 6 tbsp |
When a recipe calls for an amount that is not in the table, scale the ratio proportionally: work out how many cups of all-purpose flour the recipe needs, then multiply the ratio by that number. For a single cup, the ratio is exactly as stated; for half a cup, halve it; for two cups, double it. Keep the recipe scaler open while you cook, and you can scale the whole recipe, including the substitution, in one step.
What changes when you use cake flour instead of all-purpose flour
Cake flour gives a lighter, more tender crumb than all-purpose flour, because it is finely milled and low in protein, so it builds very little gluten. In a sponge cake, the difference is dramatic: the cake rises higher, feels softer and melts in the mouth, which is exactly what cake flour is made for. In a cookie, the difference is subtler: the cookies spread a little more and turn out more delicate, which suits a shortbread but not a chewy cookie. In a yeasted bread, the difference is a problem: cake flour has too little protein to build the gluten network a bread needs, so the loaf turns out flat and dense. The flavour does not change, because both flours are white wheat flour, but the texture changes in every recipe, and the batter feels slightly softer, because cake flour absorbs less water.
When not to substitute all-purpose flour with cake flour
Do not swap flours 1:1 in delicate cakes or yeasted breads without adjusting liquid and expecting a different crumb. That rule is the most important part of this page, because a substitution that works in one recipe can fail badly in another. All-purpose flour does a specific job in each recipe, and the swap only works when the substitute can do the same job. In a recipe where all-purpose flour is the main structure — where it holds the bake together, or where its flavour is the point of the dish — the substitute will not do, and it is better to wait until you have the real ingredient, or to choose a different recipe. In a recipe where all-purpose flour is a supporting ingredient, where it adds moisture, richness or flavour but does not carry the dish, the swap usually works well. The test is simple: if removing the all-purpose flour would ruin the recipe, do not substitute it; if the recipe would still work without it, the substitute is probably safe.
Why this swap works
Flours differ in protein and absorption; swapping changes texture, so start with the ratio and check the dough. That is the principle behind the swap: the substitute does the same chemical or structural job as the original, even though it looks and tastes different. The acid in an acidic substitute activates baking soda, the fat in a fatty substitute shortens a dough, and the liquid in a liquid substitute hydrates the flour. When the substitute does the same job, the swap works; when it does a different job, the swap fails. The ratio on this page is the amount that makes the substitute do the same job as the original, and it is worth following exactly, rather than guessing, because a small error in the ratio changes the job the substitute does.
Worked examples: all-purpose flour to cake flour in real recipes
1. A light sponge cake for a birthday
A sponge cake needs two cups of all-purpose flour, so use two cups plus 4 tablespoons of cake flour, measured carefully. The cake flour gives the sponge a lighter, more tender crumb that melts in the mouth, and the extra flour matters, because cake flour is lighter per cup. Sift the flour before measuring, fold the batter gently, and bake the cake in a moderate oven, because a light sponge burns easily if the oven is too hot.
2. A delicate shortbread for afternoon tea
A shortbread needs a cup of all-purpose flour, so use a cup plus 2 tablespoons of cake flour. The cake flour gives the shortbread a finer, more delicate crumb that melts in the mouth, which suits a shortbread better than the coarser crumb of all-purpose flour. Cream the butter and sugar well, press the dough into the tin, and chill it before baking, so the fingers hold their shape.
3. A chiffon cake that needs a tender crumb
A chiffon cake needs three cups of all-purpose flour, so use three cups plus 6 tablespoons of cake flour. The cake flour gives the chiffon its light, airy texture, and the extra flour is essential, because a chiffon made with too little flour sinks in the middle. Sift the flour twice, fold the beaten egg whites in gently, and bake the cake in an ungreased tin, so it can climb the sides as it rises.
How to make the swap
Measure 1 cup plus 2 tablespoons of cake flour for every cup of all-purpose flour, and use it in the same place in the recipe. The extra 2 tablespoons matter, because cake flour is lighter per cup than all-purpose flour, so a straight cup-for-cup swap leaves the batter short on flour. Sift the cake flour before measuring, or spoon it lightly into the measure and level it, because cake flour packs easily and a scooped cup can be much heavier. For a sponge cake, the swap is an improvement, and the cake will be lighter and more tender. For a cookie, expect a more delicate result, and chill the dough if the cookies spread too much. For a bread, do not make the swap, because cake flour cannot build the gluten a bread needs.
Common mistakes
The most common mistake is swapping cake flour cup-for-cup without adding the extra 2 tablespoons, which leaves the batter short on flour and makes the cake sink. Always add the extra 2 tablespoons per cup. The second mistake is scooping cake flour straight from the bag, which packs it and over-measures by a lot; spoon it lightly and level it, or sift it first. The third mistake is using cake flour in a yeasted bread, which turns out flat and dense, because cake flour has too little protein. Finally, do not use cake flour in a recipe that needs structure, such as a pastry or a pizza dough, because the low protein cannot build the gluten the recipe needs.
Frequently asked questions
How much cake flour replaces 1 cup of all-purpose flour?
Use 1 cup plus 2 tablespoons of cake flour per cup of all-purpose flour. Cake flour is lighter per cup than all-purpose flour, so a straight cup-for-cup swap leaves the batter short on flour and the cake can sink. The extra 2 tablespoons make up the difference, and the cake turns out light and tender.
Can I substitute cake flour for all-purpose flour 1:1?
No, not without adjusting. Cake flour is lighter per cup, so you need 1 cup plus 2 tablespoons of cake flour per cup of all-purpose flour. A straight 1:1 swap leaves the batter short on flour, and the cake can sink in the middle or turn out too soft to hold its shape.
Will cake flour make my cake lighter?
Yes. Cake flour is finely milled and low in protein, so it builds very little gluten, and the crumb is lighter, softer and more tender than an all-purpose cake. The difference is most noticeable in a sponge cake or a chiffon cake, where the light texture is the whole point, and less noticeable in a cookie or a muffin.
Can I use cake flour in bread?
It is better not to. Cake flour has too little protein to build the gluten network a bread needs, so a loaf made with cake flour turns out flat and dense, with a poor crumb. For bread, use bread flour or all-purpose flour, which have enough protein to build the structure the loaf needs.
Should I sift cake flour before measuring?
Yes, or spoon it lightly into the measure and level it. Cake flour is very fine and packs easily, so a scooped cup can be much heavier than a spooned and levelled one. Sifting adds air and gives a consistent measure, and it also removes any lumps, which is important for a light sponge cake.