How Many Grams of Flour Are in a Cup
One cup of all-purpose wheat flour weighs 120 grams. That’s the figure you need if your recipe is written in cups but you work with a scale. But be careful: not all flours weigh the same, and the way you fill the cup can change the result by up to 20 grams. Here are the exact figures for each case.
How many grams of flour are in a cup (the key figure)
The standard baking equivalence is:
- 1 cup of all-purpose flour = 120 grams
- 3/4 cup of flour = 90 grams
- 1/2 cup of flour = 60 grams
- 1/3 cup of flour = 40 grams
- 1/4 cup of flour = 30 grams
This 120 g figure corresponds to the US measuring cup of 240 ml, the one used in most English-language recipes. If your recipe specifies something else (cake flour, whole wheat, self-rising), the weight changes.
How much a cup of flour weighs by type
Not all flour has the same density. These are the equivalences by type, always for a 240 ml cup:
- All-purpose flour: 120 g
- Cake flour: 115 g
- Whole wheat flour: 130 g
- Self-rising flour: 125 g
- Bread flour: 127 g
The difference between the lightest and the heaviest is up to 15 grams per cup. In a recipe using 3 cups, that’s 45 grams more or less, enough to make a cake turn out dry or too moist.
Why the filling method changes the weight
The most common mistake when measuring flour with cups is compacting it without realizing it. There are three ways to fill a cup, and each gives a different result:
- Scooping the cup directly into the flour bag and packing it down: up to 150 g
- Spooning the flour into the cup without pressing and leveling it off: 120 g (the correct method)
- Sifting the flour before filling the cup: can drop to 110 g
The technique recommended by American baking books is ‘spoon and level’: stir the flour in its bag to aerate it, spoon it into the cup without pressing, and run the back of a knife over the top to remove the excess. Never plunge the cup directly into the bag.
Flour cup to gram conversion: quick fraction table
If your recipe calls for fractional amounts, this table saves you the calculation:
- 2 cups of flour = 240 g
- 1 1/2 cups of flour = 180 g
- 1 1/4 cups of flour = 150 g
- 2/3 cup of flour = 80 g
- 1/8 cup of flour = 15 g
For any amount not listed here, multiply the number of cups by 120 to get the grams. Half a cup plus a bit more (0.6 cups) is 72 grams, for example.
Differences between US cups, metric cups, and other measures
The cup we use in baking (240 ml) is not universal. There are other versions that can confuse you if you copy a recipe from another country:
- US cup: 240 ml → 120 g of flour
- Metric cup (used in Australia, the UK, New Zealand): 250 ml → approximately 125 g of flour
- Japanese cup: 200 ml → approximately 100 g of flour
If a recipe doesn’t specify the origin of the cup, assume it’s the US 240 ml cup unless the rest of the context (brand, language, ingredients) indicates otherwise.
Why it’s better to weigh flour instead of using cups
Professional bakers weigh almost everything. The reason is simple: a scale always gives the same result, while a cup depends on how you fill it, on the flour’s ambient humidity, and on whether you sifted it beforehand or not. For a recipe that needs precision (macarons, bread, puff pastry), a margin of error of 20 grams per cup can ruin the final texture.
If you work with recipes in pounds or ounces in addition to cups, it’s worth having a grams to ounces calculator on hand to switch between systems without mental math errors.
How flour’s moisture affects its real weight
Flour absorbs moisture from the environment. In humid climates, the same cup can weigh 3-5 grams more than in a dry environment, because the particles retain water and compact differently. It’s a small difference for most home recipes, but it shows in precision baking where every gram matters for the gluten structure.
If you notice your doughs turning out drier or wetter than expected depending on the season, this is probably the reason, not a mistake in the recipe.
Common mistakes when converting flour from cups to grams
These are the most frequent errors when someone starts weighing their ingredients:
- Using the same equivalence for flour as for sugar or cocoa (each ingredient has its own density)
- Compacting the flour in the cup without noticing, adding up to 30 g extra
- Not distinguishing between cake flour and all-purpose flour, which weigh differently
- Converting mentally without checking whether the recipe uses a US or metric cup
If you convert baking recipes frequently, it’s worth checking out how to convert an American recipe from cups to grams step by step, because flour is rarely the only ingredient that needs converting.
Flour alongside other ingredients: equivalences you’ll want to know
Almost no recipe uses only flour. If you’re converting a whole recipe, you’ll also want to know how many grams of butter are in a cup, another key ingredient in most doughs and cakes where an imprecise measurement changes the final texture.
Frequently asked questions
How many grams of flour are in a cup?
One cup of all-purpose flour equals 120 grams, using the US measuring cup of 240 ml and the spoon-and-level filling method without packing it down.
How much does a cup of whole wheat flour weigh?
A cup of whole wheat flour weighs approximately 130 grams, a bit more than regular white flour because it retains the bran and germ of the grain, which add more weight per volume.
Is measuring flour with a cup the same as with a scale?
Not exactly. Measuring with a scale always gives an exact, repeatable result, while measuring with a cup depends on how you fill it: it can vary between 100 and 150 grams depending on whether you pack the flour down or spoon it in without pressing.
Why does my recipe turn out different using US or metric cups?
Because the US cup measures 240 ml and the metric cup used in countries like the UK or Australia measures 250 ml. That 10 ml difference translates into about 5 grams more flour per cup if you use the metric one without adjusting.
How many grams is half a cup of flour?
Half a cup of all-purpose flour equals 60 grams, following the same proportion of 120 grams per full cup.