There are about 8.3 cups in a kilogram of cake flour — approximately, because the figure depends on how the flour is measured. One US cup of cake flour weighs 120 g spooned and levelled, so 1,000 g divided by 120 g gives about 8.33 cups. That is the short answer, and the rest of this guide explains where the number comes from, how much it moves when the measuring method changes, and how to use it in real recipes — from a single cake to a bakery-scale bake.

Cake flour weighs the same as all-purpose flour — 120 g per cup, about 8.3 cups per kilogram — but it is a different ingredient in every way that matters. It is milled finer, it has less protein, and it makes a tender, delicate crumb that all-purpose flour cannot match. The kilogram figure is the same; the cakes are not.

Every figure on this page is labelled approximate, and for good reason: cup measurements vary with packing, moisture and the size of the pieces. When a recipe depends on the amount — a cake, a loaf of bread, a jam that has to set — weigh the ingredient on a kitchen scale instead of trusting the cup. The scale is the only measuring tool that does not care how you filled the cup.

The conversion at a glance

One cup of cake flour weighs 120 g spooned and levelled. A kilogram is 1,000 g, so the arithmetic is 1,000 ÷ 120 = about 8.33 cups. The table below gives the cup equivalents for the amounts you are most likely to meet, whether you are scaling a recipe up or working out how far a bag will go. All figures are approximate, and all of them use the same 120 g per cup.

Amount Grams Cups (approx.) Tablespoons (approx.)
100 g 100 g 0.8 cups 13 tbsp
250 g 250 g 2.1 cups 33 tbsp
500 g 500 g 4.2 cups 67 tbsp
1 kg 1000 g 8.3 cups 133 tbsp
2 kg 2000 g 16.7 cups 267 tbsp
5 kg 5000 g 41.7 cups 667 tbsp

A single tablespoon of cake flour weighs about 7.5 g, and a teaspoon about 2.5 g — useful when a recipe calls for a spoonful rather than a cup. Note that a kilogram is about 2.2 lb, so the same kilogram works out to about 8.3 cups by the pound route as well: the two routes agree, because they are the same arithmetic with the same density. If you buy flour in pounds rather than kilograms, one pound of cake flour is about 3.8 cups.

Worked examples

A kilogram of cake flour and a season of sponge cakes

A sponge cake needs about 2 cups of cake flour, about 240 g, so a 1 kg bag makes four sponges with a third of a cup left over. A baker making a sponge every weekend goes through a kilogram in a month. Cake flour is used in smaller amounts than bread flour, so the bag lasts longer — but it also goes stale faster once opened, because the fine milling exposes more surface area. Keep it sealed and use it within six months.

A chiffon cake for a celebration

Chiffon cake is the recipe that justifies cake flour. A chiffon for twelve needs about 2.5 cups of cake flour, about 300 g, whipped with egg whites for a tall, airy crumb. A kilogram covers three chiffons. Sift the flour twice before folding it in: cake flour clumps more readily than all-purpose, and an unsifted lump of flour in a chiffon is a dense spot in an otherwise feather-light cake.

A batch of delicate cupcakes

Cupcakes are the everyday use for cake flour. A batch of 24 cupcakes needs about 3 cups of cake flour, about 360 g, and a kilogram covers two batches with a little to spare. Do not overmix the batter: cake flour's low protein is what makes the crumb tender, but overmixing develops even that small amount of gluten, and the cupcakes turn tough. Mix until the flour just disappears, then stop.

How the figure is measured

The headline figure comes from the CookScale ingredient table, which lists cake flour at 120 g per US cup (236.6 ml), spooned and levelled, sourced from King Arthur Baking with high confidence. Very finely milled, low-protein flour that gives cakes a tender, fine crumb. The table's uses for cake flour are: Sponge cakes, chiffon and delicate layer cakes.

A note on disputed figures: 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.

The method matters more than most people realise. Spooned and levelled is the standard for this ingredient, and a different method gives a different weight: scooping instead of spooning compresses dry ingredients and can add 10–20% to the weight of a cup, while packing a sticky ingredient can add even more. That is why this guide states the method alongside every figure, and why the headline number is always labelled approximate. If you measure differently from the stated method, expect a different result — and if the recipe matters, weigh the ingredient instead.

One practical consequence: never convert in the wrong direction by accident. To go from cups to grams, multiply the cups by 120. To go from grams to cups, divide the grams by 120. To go from kilograms to cups, divide the grams (1,000 per kilogram) by 120. Keep the 120 g figure in mind and the rest is simple division — but always check the result against a scale when the bake depends on it.

Practical guidance

The mistake is substituting all-purpose flour for cake flour cup-for-cup and expecting the same cake. The weight is the same, but all-purpose flour has more protein and a coarser milling, so the cake turns out denser and less tender. If you must substitute, use 1 cup of all-purpose flour minus 2 tablespoons, plus 2 tablespoons of cornstarch, for each cup of cake flour — the cornstarch lowers the protein and mimics the fine texture.

Storage: Airtight container, cool and dry, up to 1 year. Weighing the ingredient before you store it, and writing the weight on the container, saves a conversion later: a tub labelled '450 g' tells you instantly that it holds about 8.3 cups, without any measuring at all.

When you do not have a scale: use the cup, but use it carefully. Spoon the ingredient into a dry measuring cup — never scoop from the bag — and level the top with the back of a knife without tapping or shaking the cup. For sticky or wet ingredients, use a liquid measuring jug and read the level at eye height, or lightly oil the cup so the ingredient releases cleanly. Accept that the result will be approximate, and if the recipe is a cake, a loaf or a jam, borrow a scale: it is the single most useful tool in baking, and it costs less than a bag of the flour it measures.

Frequently asked questions

How many cups are in 1 kg of cake flour?

About 8.3 cups. One cup of cake flour weighs 120 g spooned and levelled, the same as all-purpose flour, and a kilogram is 1,000 g, so 1,000 divided by 120 gives about 8.3 cups. A 500 g bag is about 4.2 cups and a 2 kg bag about 16.7 cups. Note that sifted cake flour is sometimes quoted at 100 g per cup — sifting adds air, so weigh sifted flour rather than measuring it by the cup.

Is cake flour the same as self-raising flour?

No. Cake flour is a low-protein, finely milled flour with no raising agents, while self-raising flour is all-purpose flour with baking powder and salt already mixed in. They are not interchangeable: a recipe written for cake flour needs you to add the leavening separately, and a recipe written for self-raising flour already has it. Using one for the other gives a cake that either does not rise or rises too much.

Why is cake flour so fine?

Because it is milled from soft wheat and ground more finely than all-purpose flour, which gives cakes a tender, even crumb with no coarse texture. The fine milling also means cake flour absorbs liquid faster and clumps more easily, which is why recipes often tell you to sift it. The weight per cup is the same as all-purpose flour — 120 g — so the conversion is identical, but the handling is different.

Should I weigh cake flour or measure it in cups?

Weigh it whenever the recipe matters. One cup of cake flour weighs 120 g spooned and levelled, but that figure assumes the stated method — and in practice, cups vary by 10–20% depending on how they are filled. A kitchen scale removes that variation entirely: 120 g is one cup, every time, regardless of who is measuring. Cups are fine for soups, salads and smoothies, where a little more or less makes no difference. For baking, jam, bread and anything where the ratio of ingredients decides the outcome, the scale is the right tool.

How accurate is the about 8.3 cups figure?

It is accurate to about plus or minus half a cup per kilogram, which is roughly the variation you get from different measuring methods and different batches of the ingredient. The figure is calculated from a single sourced density — 120 g per cup from King Arthur Baking, high confidence — and the arithmetic is exact: 1,000 ÷ 120 = 8.33 cups. The uncertainty is not in the maths but in the cup itself: a scooped cup weighs more than a spooned cup, and a packed cup weighs more than a loose one. Treat 8.3 cups as a planning figure and verify with a scale when it matters.

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