How Many Grams Are in a Cup of Flour?
One US cup of all-purpose flour weighs about 120 grams when spooned into the cup and levelled off.
Why This One Is Not Exact
Every other conversion on this site is a definition: an inch is exactly 2.54 centimeters, and that never changes. This page is different. A cup measures volume and grams measure weight, and what bridges them is density — which depends on the ingredient and, far more, on how the cup was filled. The figure of 120 grams per cup is the standard reference, not a law of nature.
Flour is the worst offender: scooping the cup through the bag packs it down and can add 20 percent, which is why serious baking recipes give grams.
Where This Comes Up
This is the conversion that separates baking that works from baking that nearly works. American recipes measure flour in cups, European ones in grams, and the two only agree if everyone fills the cup the same way — which they do not.
A cookie recipe calling for 2 cups of flour wants about 240 grams — but 290 grams if you scooped, which is the difference between chewy and dry.
What People Get Wrong
How you fill the cup matters more than which cup you use. Dipping the cup into the bag compacts the flour and can give 145 grams instead of 120, which is 20 percent more flour than the recipe wanted. Spoon it in loosely and level it off with a knife.
All-Purpose Flour Cups to Grams Chart
| Recipe calls for | Grams | Ounces |
|---|---|---|
| 1 tablespoon | 8 | 0.26 |
| 1/8 cup | 15 | 0.53 |
| 1/4 cup | 30 | 1.06 |
| 1/3 cup | 40 | 1.41 |
| 1/2 cup | 60 | 2.12 |
| 2/3 cup | 80 | 2.82 |
| 3/4 cup | 90 | 3.17 |
| 1 cup | 120 | 4.23 |
| 1 1/2 cups | 180 | 6.35 |
| 2 cups | 240 | 8.47 |
| 3 cups | 360 | 12.7 |
| 4 cups | 480 | 16.93 |
Weights follow the King Arthur Baking ingredient weight chart, the reference most American recipes are written against. For the exact, defined conversions used elsewhere on this site, see how we calculate.
Frequently Asked Questions
Is a cup of flour 120 or 125 grams?
Both figures are in circulation. King Arthur Baking uses 120 grams and most European conversions use 125; the difference is smaller than the error introduced by how you fill the cup, so either is fine as long as you are consistent.
Why do bakers weigh flour instead of measuring it?
Because volume measurement of a compressible powder is unreliable. A scale removes the variable entirely, which is why professional recipes are written in grams.
How many grams is half a cup of flour?
About 60 grams, using the 120 grams per cup figure.
Does bread flour weigh the same as all-purpose?
Yes, about 120 grams per cup. The difference between them is protein content, not density.