Cake Flour Substitute
No cake flour? For every 1 cup of cake flour, whisk together ¾ cup + 2 tbsp of all-purpose flour (105 g) and 2 tbsp of cornstarch (14 g) — the rule King Arthur Baking, America's Test Kitchen and Bob's Red Mill all agree on. Enter any amount to get the blend, measured or in grams.
One amount, three phrasings: ¾ cup + 2 tbsp, ⅞ cup and 1 cup minus 2 tbsp are all exactly 14 tablespoons of flour — sources word the same rule differently. But watch for a garbled copy that circulates widely (even on a university extension page): plain "¾ cup of all-purpose flour plus 2 tbsp cornstarch" quietly drops 2 tablespoons of flour and shorts the recipe.
Cake flour substitute chart
| Cake flour needed | All-purpose flour | Flour (g) | Cornstarch | Cornstarch (g) |
|---|---|---|---|---|
| ¼ cup | 3½ tbsp | 26 g | 1½ tsp | 3.5 g |
| ⅓ cup | ¼ cup + 2 tsp | 35 g | 2 tsp | 4.7 g |
| ½ cup | ¼ cup + 3 tbsp | 53 g | 1 tbsp | 7 g |
| ⅔ cup | ½ cup + 1 tbsp + 1 tsp | 70 g | 1 tbsp + 1 tsp | 9.3 g |
| ¾ cup | ½ cup + 2½ tbsp | 79 g | 1½ tbsp | 11 g |
| 1 cup | ¾ cup + 2 tbsp | 105 g | 2 tbsp | 14 g |
| 1¼ cups | 1 cup + 1½ tbsp | 131 g | 2½ tbsp | 18 g |
| 1½ cups | 1 ¼ cups + 1 tbsp | 158 g | 3 tbsp | 21 g |
| 2 cups | 1 ¾ cups | 210 g | ¼ cup | 28 g |
| 3 cups | 2 ½ cups + 2 tbsp | 315 g | ¼ cup + 2 tbsp | 42 g |
Whisk the two together thoroughly before using (King Arthur's instruction). Bob's Red Mill suggests sifting the blend — up to five times — for the airiest cakes; sifting isn't mandatory, but it does distribute the cornstarch evenly.
Why the cornstarch works
Cake flour is simply lower-protein flour: classic bleached cake flour runs about 6–9% protein against roughly 10–12% for all-purpose (King Arthur's unbleached cake flour is a narrower 10% vs 11.7%). Cornstarch contains essentially no protein, so replacing part of the flour with it dilutes the blend's protein toward cake-flour territory. Less protein → less gluten when the batter is mixed → the fine, tender, melt-away crumb cake flour is famous for. The cornstarch also brings some extra tenderness of its own.
Cake flour substitute by weight (grams)
Baking by scale? King Arthur's blend is 105 g all-purpose flour + 14 g cornstarch per cup of cake flour, and they state it substitutes by equal weight or volume — so for a metric recipe, split the recipe's cake-flour grams roughly 88% flour : 12% cornstarch:
| Cake flour called for | All-purpose flour | Cornstarch |
|---|---|---|
| 100 g | 88 g | 12 g |
| 150 g | 132 g | 18 g |
| 200 g | 176 g | 24 g |
| 250 g | 221 g | 29 g |
| 300 g | 265 g | 35 g |
| 500 g | 441 g | 59 g |
Honest footnote for scale bakers: Cook's Illustrated publishes a noticeably starchier blend — about 20 g of cornstarch per 100 g of flour — while its sibling America's Test Kitchen page matches the King Arthur ratio. The rule has slack; more cornstarch leans more tender.
The no-cornstarch variant
Older substitution charts — still published by Virginia Cooperative Extension — skip the cornstarch entirely: use 1 cup minus 2 tbsp of all-purpose flour per cup of cake flour and stop there. That version reduces the amount of flour (and so total gluten) rather than the protein percentage, and it works acceptably in sturdy cakes. If there's cornstarch in the pantry, the blend above gets closer to the real thing.
The reverse: using cake flour in an all-purpose recipe
Going the other way — the recipe says all-purpose, and you'd like a finer crumb — use 1 cup + 2 tbsp of cake flour per cup of all-purpose (the Swans Down and Utah State University Extension rule; cake flour is lighter, so it takes a little more of it):
| All-purpose called for | Cake flour to use | Cake flour (g) |
|---|---|---|
| ½ cup | ½ cup + 1 tbsp | 68 g |
| 1 cup | 1 cup + 2 tbsp | 135 g |
| 1½ cups | 1 ½ cups + 3 tbsp | 203 g |
| 2 cups | 2 ¼ cups | 270 g |
Keep the swap to tender bakes. King Arthur cautions that cake flour pushed 1:1 into a recipe developed for all-purpose can give sunken cakes and bars, or cookies too delicate to hold together. And if the recipe calls for cake flour and you'd rather just use plain all-purpose 1:1 (by weight), that works too — expect a slightly coarser, sturdier crumb.
Where the substitute shines — and where it doesn't
Use it confidently: butter and oil cakes, cupcakes, snack cakes, muffins, pancakes and biscuits — anywhere cake flour is there for tenderness.
Think twice: angel food, chiffon and pure white cakes, which are usually developed around real bleached cake flour (America's Test Kitchen notes it produces a loftier cake than unbleached flour). The blend still bakes up fine there — just a touch shorter and coarser. And don't reach for self-rising flour: it's flour plus baking powder and salt, which the recipe didn't ask for.
Need a different conversion?
Just weighing, not substituting? 1 cup of cake flour is 120 g and 1 cup of all-purpose flour is 120 g (cornstarch: 112 g) — the flour conversion chart covers every flour on the site. Swapping other ingredients? The butter to oil conversion and the sugar to honey conversion work the same way: a fixed ratio plus honest adjustments. Halving the recipe while you're at it? See the recipe halving chart.
Frequently asked questions
How do I make 1 cup of cake flour from all-purpose flour?
Measure 1 cup of all-purpose flour, remove 2 tablespoons, then add 2 tablespoons of cornstarch and whisk to combine. That's 3/4 cup + 2 tbsp of flour (105 g) plus 2 tbsp of cornstarch (14 g) — the same rule King Arthur Baking, America's Test Kitchen and Bob's Red Mill all publish. Use the blend in place of cake flour, measure for measure.
Is it 3/4 cup or 7/8 cup of all-purpose flour?
Both — they're the same amount. 3/4 cup + 2 tablespoons, 7/8 cup, and 1 cup minus 2 tablespoons are all exactly 14 tablespoons. Watch out for a garbled version in circulation (it even appears on a university extension page): a plain '3/4 cup of all-purpose flour plus 2 tablespoons of cornstarch' silently drops 2 tablespoons of flour and shorts the recipe by an eighth of a cup.
Can I substitute all-purpose flour without adding cornstarch?
You can — it's a real published convention, not a mistake. Virginia Cooperative Extension's substitution chart says 1 cup minus 2 tablespoons of all-purpose flour per cup of cake flour, with no cornstarch. It reduces the amount of flour rather than the protein percentage, so the crumb lands a little closer to an everyday all-purpose bake. If you have cornstarch, the blend gets you closer to true cake flour.
Do I sift or whisk the flour and cornstarch together?
King Arthur Baking says simply whisk them together. Bob's Red Mill goes the other way and advises sifting — as many as five times — for the fluffiest cakes. Sifting distributes the cornstarch evenly and adds air, but no primary source treats it as mandatory; whisking thoroughly is the accepted minimum.
Why does adding cornstarch make all-purpose flour act like cake flour?
Dilution. Cornstarch is essentially protein-free, so cutting all-purpose flour with it lowers the blend's overall protein content toward cake flour's. Less protein means less gluten develops when the batter is mixed, and that's what gives cake-flour bakes their fine, tender crumb. King Arthur, America's Test Kitchen and Bob's Red Mill all describe it the same way.
What is the protein difference between cake flour and all-purpose flour?
Classic bleached cake flour (Swans Down style) runs about 6–9% protein versus roughly 10–12% for all-purpose — the ranges America's Test Kitchen and Bob's Red Mill publish. One nuance: King Arthur's unbleached cake flour is 10% protein against their 11.7% all-purpose, a much smaller gap. Either way, cake flour is the lowest-protein wheat flour on the shelf.
How do I make cake flour by weight?
For every 100 g of cake flour a recipe calls for, whisk together 88 g of all-purpose flour and 12 g of cornstarch. That's King Arthur's 105 g + 14 g per-cup blend scaled down — they state it substitutes for cake flour by equal weight or volume. (Cook's Illustrated publishes a starchier mix — about 20 g of cornstarch per 100 g of flour — proof the ratio has some slack.)
How much does a cup of cake flour weigh?
It depends on the brand more than people expect. King Arthur lists its unbleached cake flour at 120 g per cup — the same as its all-purpose flour. Bob's Red Mill and Swans Down package labels work out to about 112 g per cup. This site's charts use the King Arthur 120 g convention.
How much cornstarch do I add to 2 cups of all-purpose flour?
Swap 2 tablespoons per cup: remove 4 tablespoons (1/4 cup) of flour from the 2 cups, then add 4 tablespoons of cornstarch. By weight that's 210 g of all-purpose flour + 28 g of cornstarch standing in for 2 cups of cake flour. The chart above spells out every common amount.
Can I use self-rising flour instead of cake flour?
No. Self-rising flour is flour with baking powder (about 1 1/2 tsp per cup) and salt already mixed in, so swapping it for cake flour adds leavening and salt the recipe never asked for — on top of the wrong protein level. Use the flour-plus-cornstarch blend instead.
My recipe calls for all-purpose flour — can I use cake flour instead?
Going that direction, use 1 cup plus 2 tablespoons of cake flour for every cup of all-purpose — the rule published by both Swans Down and Utah State University Extension. Expect a more delicate result, and don't push it into sturdy bakes: King Arthur cautions that cake flour swapped 1:1 into a recipe built for all-purpose can mean sunken cakes or cookies that fall apart.
Does the substitute work for angel food or chiffon cake?
It's weakest there. The blend is great in everyday butter cakes, cupcakes, muffins and snack cakes. The most delicate high-egg-white bakes — angel food, chiffon, pure white cakes — are usually developed around real bleached cake flour, which America's Test Kitchen notes produces a loftier cake. The substitute will still bake up fine, just a little less tall with a slightly coarser crumb.