1/3 Cup Cake Flour in Grams
1/3 cup of cake flour weighs 40 g (spooned and levelled, King Arthur Baking). Very finely milled, low-protein flour that gives cakes a tender, fine crumb. All the figures on this page are approximate conversions based on the King Arthur Baking value of 120 g per cup, so when a recipe really matters, verify with a kitchen scale.
Why a third of a cup is worth weighing
A third of a cup is a small measure, and small measures are where cup errors hurt most. A 5 g mistake in a full cup of cake flour is a rounding error; the same 5 g on 40 g is a much bigger swing, and in a small batch that swing can change the result. Recipes that call for 1/3 cup are usually small, precise or both, and there is no large batch to absorb the error. Weighing 40 g takes five seconds and removes the problem entirely.
Cake Flour cups to grams conversion table
| Cups | Grams | Tablespoons |
|---|---|---|
| 1/4 cup | 30 g | 4 |
| 1/3 cup | 40 g | 5.3 |
| 1/2 cup | 60 g | 8 |
| 2/3 cup | 80 g | 10.7 |
| 3/4 cup | 90 g | 12 |
| 1 cup | 120 g | 16 |
| 1 1/2 cups | 180 g | 24 |
| 2 cups | 240 g | 32 |
The tablespoon column shows how many tablespoons each amount equals: 1/3 cup is 5.3 tablespoons, and one tablespoon of cake flour weighs about 7.5. A cup is 16 tablespoons, so the numbers in the table are just the cup weight divided by 16, rounded to one decimal place. For small amounts a scale that reads to the gram is far more reliable than a spoon, because a heaped tablespoon can weigh half as much again as a level one. Read the table from the 1/3 cup row outwards: every other row is a multiple of 40 g, so scaling a recipe up or down is simple multiplication.
How the weight was measured
Spooned and levelled means the ingredient is measured the way King Arthur Baking measures it: spooned and levelled. For cake flour, that gives 120 g per cup, and a third of a cup of that is 40 g. The source for the figure is King Arthur Baking, and the confidence in the value is high. King Arthur Baking publishes a standard ingredient weight chart that recipe developers use as a reference, and this page follows it exactly rather than averaging across sources, because an average of two different measuring methods is a number that matches nobody's cup.
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. That is why this page uses the King Arthur Baking value of 120 g per cup as its single, stated source, rather than averaging across charts. If a recipe you trust uses a different figure, follow that recipe's chart for that recipe — but do not mix charts inside one recipe.
Worked examples
Scaling a recipe that calls for 1/3 cup
A recipe for a rustic loaf calls for 1/3 cup of cake flour, and you want to make one and a half times as much for guests. On the scale that is simple: 40 g times 1.5 is 60 g, and you weigh it straight into the bowl. Doing the same sum in cups means measuring a cup and an eighth, which no measuring cup marks, so most people guess — and guessing is how a good recipe goes wrong. The same logic works in reverse: halve the recipe and you need 20 g, which is 20 g on the scale and a fiddly 2.6 tablespoons by volume. cake flour is used for sponge cakes, chiffon and delicate layer cakes, and the weighed amount keeps the ratio right at any scale.
A small batch built around 1/3 cup
Sometimes 1/3 cup is the whole point of the recipe, not a fraction of it. A small batch of a shortcrust pastry for two people often needs just 1/3 cup of cake flour — 40 g — alongside the other ingredients, and at that scale there is nothing to hide behind: too much and the result is heavy or overpowering, too little and it is bland or falls apart. Weigh the 40 g first, before you start mixing, so you know the foundation is right. Once you know that 1/3 cup is 40 g, you can scale the same recipe up for four people by doubling to 80 g without ever touching a measuring cup, and the result will taste the same.
Doubling and halving from 1/3 cup
Halving a recipe is where 1/3 cup appears most often in real kitchens. A recipe written for a family might call for 1 1/2 cups of cake flour; halved, that is 1/3 cup, or 40 g. The trap is halving by volume: half of 1 1/2 cups is easy to say and hard to measure, because few cup sets have a 3/4-cup measure and fewer still have a 1/3-cup one. Weighing 40 g sidesteps the problem entirely. And if you are doubling instead, two lots of 1/3 cup is 1 1/2 cups, which is 80 g — again, one number on the scale, no cup juggling, and the recipe stays in proportion.
When the conversion matters most
1/3 cup of cake flour shows up in recipes where the ratio is doing real work. cake flour is used for sponge cakes, chiffon and delicate layer cakes, and in those recipes the amount is not decoration — it sets the texture, the structure or the flavour balance. In a sauce or a dressing, a few extra grams of cake flour can tip the balance; in a baked good, they can change the crumb. That is why recipes written in grams are worth following in grams: the recipe writer tested 40 g, not a cup that happened to be full that day. If you are cooking by feel, a cup is fine; if you are baking to a recipe, weigh it. The difference between the two approaches is the difference between a recipe that works every time and one that works on a good day.
Scaling 1/3 cup up and down
Once you know that 1/3 cup of cake flour is 40 g, the rest is arithmetic. A full cup is 120 g, half a cup is 60 g, and two cups is 240 g. Doubling a recipe that calls for 1/3 cup means weighing 80 g; halving it means 20 g, which is about 2.6 tablespoons. Writing the recipe in grams at this point is worth doing: the next time you make it, you weigh 40 g straight into the bowl and skip the measuring cup altogether. If you are scaling a recipe for a different tin size, convert every ingredient to grams first and then multiply — scaling by volume compounds the error on every ingredient at once, while scaling by weight keeps each one exact.
Common mistakes with cake flour
- Scooping the cup from the bag. Scooping packs the ingredient down and can add several grams per cup. Always spoon and level, or weigh 40 g.
- Scooping the cup from the bag. Scooping packs the flour down and can add several grams even to a third of a cup. Always spoon and level, or weigh 40.
- Measuring over the mixing bowl. Levelling over the bowl drops the excess straight into the batter, so you have added cake flour you did not intend. Level over the bag or the sink.
- Measuring over the mixing bowl. Levelling over the bowl drops the excess straight into the batter. Level over the bag or the sink.
Storage and handling
Airtight container, cool and dry, up to 1 year. Keeping cake flour stored properly also keeps its weight per cup stable: an ingredient that has absorbed moisture from the air weighs more per cup than a dry one, so a sealed container is not just about freshness, it is about measurement accuracy too. If a bag has been open for months in a humid kitchen, the first thing to do before a precise bake is to weigh the ingredient rather than trusting the cup. Label the container with the conversion — 1/3 cup is 40 g — and the next person to bake with it will thank you.
Frequently asked questions
How many grams is 1/3 cup of cake flour?
1/3 cup of cake flour weighs 40 g, measured spooned and levelled according to King Arthur Baking. That is a third of a cup of the full-cup weight of 120 g, and it is the figure to use when converting a recipe from cups to grams. All the figures on this page are approximate, so when a recipe really matters, verify with a kitchen scale.
How many tablespoons is 1/3 cup of cake flour?
There are 5.3 tablespoons in 1/3 cup, whatever the ingredient. One tablespoon of cake flour weighs about 7.5, so 5.3 tablespoons come to about 40 g. For amounts like this, a scale that reads to the gram is more reliable than spoons, because a heaped tablespoon can weigh half as much again as a level one.
How do I measure 1/3 cup of cake flour without a scale?
Cake flour is measured spooned and levelled, according to King Arthur Baking. Spoon it into a 1/3 cup measure, level the top with the back of a knife, and you will be close to 40 g. That is the best you can do without a scale — but be honest with yourself that it is an estimate. A basic digital kitchen scale costs less than a bag of good ingredients and removes the guesswork from every recipe, not just this one.
What is cake flour used for?
Sponge cakes, chiffon and delicate layer cakes. Very finely milled, low-protein flour that gives cakes a tender, fine crumb. 1/3 cup — 40 g — is a common amount in small batches and scaled recipes, which is why this conversion comes up so often.
How should I store cake flour?
Airtight container, cool and dry, up to 1 year. Good storage keeps the ingredient fresh and keeps its weight per cup consistent, because moisture absorbed from the air adds grams that the recipe did not ask for.
Why do different charts give different weights for cake flour?
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. We use the King Arthur Baking figure of 120 g per cup, measured spooned and levelled, so 1/3 cup is 40 g. If a recipe you trust uses a different figure, follow that recipe's chart for that recipe — but do not mix charts inside one recipe.
Related conversions
Use the cups to grams converter flour substitute converter recipe scaler cups to grams hub for instant answers, or browse the cups to grams hub for the full ingredient list. Related pages: 1 cup of cake flour in grams, 120 g of cake flour in cups, tablespoons of cake flour in grams, cake flour guide, 1/3 Cup All-Purpose Flour in Grams, 1/3 Cup Bread Flour in Grams. See also our disclaimer about approximate conversions.