If you have run out of cake flour and the cupboard holds all-purpose flour, you do not need to abandon the bake. The ratio is 3/4 cup + 2 tbsp all-purpose flour per cup of cake flour — and in a forgiving recipe such as muffins, pancakes or a quick bread, you can make the swap and carry on. What you should not do is treat the two flours as identical, because they are not: they differ in protein, in how much water they absorb, and in how they behave in the oven. Those differences are small in a batter and large in a dough, which is why the same swap can be invisible in one recipe and obvious in the next.
This page gives you the conversion table for every amount you are likely to meet, three worked examples with real numbers, and an honest account of what changes in the result — flavour, texture, rise and keeping quality — plus the recipes where you should not substitute at all. Flours differ in protein and absorption; swapping changes texture, so start with the ratio and check the dough. Keep that in mind as you read: the ratio is fixed, but how much of the flour you replace is a judgement call, and this page helps you make it.
The ratio, in a table
The table below converts cake flour to all-purpose flour for the amounts you are most likely to meet. The rule is always the same: 3/4 cup + 2 tbsp all-purpose flour per cup of cake flour.
| Cake flour called for | All-purpose flour to use | Approximate weight | Notes |
|---|---|---|---|
| 1/4 cup | 3 tablespoons + 1 1/2 teaspoons of all-purpose flour | about 26 g | |
| 1/3 cup | 1/4 cup + 2 teaspoons of all-purpose flour | about 35 g | |
| 1/2 cup | 3/8 cup + 1 tablespoon of all-purpose flour | about 52 g | |
| 2/3 cup | 1/2 cup + 1 tablespoon + 1 teaspoon of all-purpose flour | about 70 g | |
| 3/4 cup | 10 tablespoons + 1 1/2 teaspoons of all-purpose flour | about 79 g | |
| 1 cup | 3/4 cup + 2 tablespoons of all-purpose flour | about 105 g | |
| 1 1/2 cups | 1 1/8 cups + 3 tablespoons of all-purpose flour | about 158 g | |
| 2 cups | 1 1/2 cups + 4 tablespoons of all-purpose flour | about 210 g |
By weight, one cup of cake flour is about 120 g and one cup of all-purpose flour is also about 120 g (King Arthur Baking, spooned and levelled), so the swap is weight-neutral at the same volume. All weights here are approximate — flour and sugar settle and pack differently depending on how they are scooped, so verify with a kitchen scale when the bake matters.
King Arthur lists 120 g per cup; finely milled cake flour is sometimes quoted at 100 g per cup when sifted, so spoon and level rather than scooping.
Worked examples
Example 1: A banana bread
Banana bread is the most forgiving place to try a flour swap, because the banana and the sugar carry the flavour and the crumb is meant to be moist and dense. A recipe calls for 1 1/2 cups of cake flour. Using the ratio, that becomes 1 1/8 cups + 3 tablespoons of all-purpose flour. Stir the batter until it just comes together — over-mixing is the real enemy here, whatever flour you use — and bake as usual. The loaf will be a little different in flavour and a little different in crumb, but in a banana bread those differences read as character rather than a mistake. This is the recipe to start with if you have never made this swap before.
Example 2: Chocolate chip cookies
Cookies show a flour swap in the spread. A recipe calls for 2 1/4 cups of cake flour. Using the ratio, that becomes about 2 cups of all-purpose flour. Cream the butter and sugar as usual, add the eggs, then mix in the flour until just combined. Chill the dough for 30 minutes before baking — chilling matters more than usual here, because a different flour absorbs liquid at a different rate and the dough needs time to hydrate evenly. Bake one test cookie first: if it spreads too much, chill the dough longer; if it stays too thick, flatten the balls slightly before baking. The flavour of the swap will be barely noticeable under the chocolate.
Example 3: A pizza dough
Pizza dough is a dough, not a batter, so it tests the flour's gluten — its strength and stretch. A recipe calls for 3 cups of cake flour. Using the ratio, that becomes 2 1/4 cups + 6 tablespoons of all-purpose flour. Mix and knead as usual, then judge the dough by feel rather than by the clock: if it feels dry and stiff, add water a tablespoon at a time; if it feels slack and sticky, add flour a tablespoon at a time. Let it rise until doubled, then stretch it out. A weaker flour will tear more easily when stretched, so handle it gently and do not try to stretch it paper-thin. The result will be a little less chewy than usual, but still a good pizza.
What changes in the result
The most visible change is usually the texture. All-Purpose Flour makes a crumb that is different in a way you can feel before you can name it — a little denser, a little more tender, or a little more open, depending on the flour. The colour changes too: a darker flour gives a darker crumb and a darker crust, and a flour with more protein browns faster. The rise can change as well, because a weaker gluten network traps less gas, so a loaf may not rise quite as high. None of this means the bake has failed. It means the bake is different, and in a forgiving recipe — a quick bread, a muffin, a brownie — different is fine. In a recipe where the flour is the star, such as a white sandwich loaf or a delicate sponge, different is the thing to watch for.
When not to substitute
Do not swap flours 1:1 in delicate cakes or yeasted breads without adjusting liquid and expecting a different crumb. In practice that means: do not make this swap in a delicate sponge or chiffon cake, where the flour is doing almost all the structural work and there is nothing to hide a difference behind. Do not make it in a yeasted bread you have never baked before, where you have no baseline to judge the dough against. Do not make it in pastry that depends on a precise gluten balance, such as puff pastry or croissants. And do not make it when the recipe is for someone with a dietary restriction you have not checked — a gluten-free blend is not automatically safe for every coeliac, and a nut flour is not safe for someone with a nut allergy. If the bake matters — a birthday cake, a loaf for guests — test the swap first in a small, forgiving recipe and judge the result before you commit to the important one.
Practical guidance
Weighing is the single best habit for this swap. A cup of flour can weigh anywhere from 120 g to 142 g depending on how it is scooped, and that 20 g spread is the difference between a good bake and a dry one. If you do not have a scale, spoon the flour into the cup and level it — never scoop — and be consistent: measure the substitute exactly the way you measured the original. Sift the substitute flour if it looks lumpy or if the recipe is a delicate cake, and let batters rest for five minutes after mixing so the flour can hydrate fully before you judge whether the batter needs more liquid.
All conversions on this page are approximate. A kitchen scale is the most reliable tool you own: weigh the substitute, note the number that works for your recipe, and use it next time. If a bake matters — a birthday cake, a loaf for guests — test the swap first in a small, forgiving recipe before you commit to the important one.
Frequently asked questions
How do I store all-purpose flour?
In an airtight container in a cool, dry place, away from heat and light. Wholegrain and nut flours go rancid faster than white flour because they contain oils, so buy them in smaller quantities and use them within a few months — the fridge extends their life. Gluten-free blends keep well sealed and dry. Always label the container with the date you opened it, and sniff the flour before you use it: rancid flour smells stale and bitter, and no recipe can rescue it.
Can I use all-purpose flour instead of cake flour in bread?
Yes, but bread is where the swap is most demanding, because the flour has to build the gluten network that holds the loaf up. Start by replacing only half the flour — for a recipe with 2 cups of flour, replace 1 cup — and judge the dough by feel. If it kneads smoothly, passes the windowpane test and rises well, you can replace more next time. If the dough tears or the loaf is dense, go back to half. The ratio is 3/4 cup + 2 tbsp all-purpose flour per cup of cake flour, and the judgement is how much of the flour to replace.
Will my cake rise the same with all-purpose flour?
Probably not exactly the same. The rise depends on the gluten network trapping gas, and all-purpose flour builds that network differently from cake flour. In a light sponge the difference is visible: the cake may be a little shorter or a little denser. In a muffin or a quick bread the difference is small enough not to matter. If the rise matters to you, replace only half the flour, and make sure your baking powder or soda is fresh — stale leavening is a more common cause of a flat cake than a flour swap.
Do I need to change the liquid when I use all-purpose flour?
Sometimes, and the answer is in the ratio itself: 3/4 cup + 2 tbsp all-purpose flour per cup of cake flour. Different flours absorb different amounts of water, so a batter made with all-purpose flour can look thicker or thinner than the same batter made with cake flour. Add liquid a tablespoon at a time until the batter looks right — a cake batter should fall from the spoon in a thick ribbon, and a bread dough should be smooth and slightly tacky. Do not add all the liquid at once, and do not trust the recipe's liquid quantity blindly after a flour swap.
Can I replace all the flour, or only some of it?
That depends on the flour and the recipe. The ratio is 3/4 cup + 2 tbsp all-purpose flour per cup of cake flour, and for many everyday bakes a full replacement works. But for delicate cakes and yeasted breads, replacing only half the flour is the safer choice — you get most of the benefit with almost none of the risk. The 'up to half' guidance in the ratio exists for exactly this reason: some flours are too strongly flavoured or too different in structure to carry a whole recipe on their own. Try half first, taste the result, and decide from there.
Does all-purpose flour change the flavour?
Yes — Flours differ in protein and absorption; swapping changes texture, so start with the ratio and check the dough. In a strongly flavoured bake such as a spice cake, a wholemeal loaf or a chocolate brownie, that flavour is an asset and most people will like it. In a plain vanilla cake or a white sauce, it is the first thing you will notice, and it may not be what you want. Match the flour to the recipe: strong flavours hide strong flours, and mild recipes need mild flours.