1 cup flour = 4.233 ounces
Volume is only half the story. All-purpose flour weighs 120 g per US cup (spooned & leveled), so we convert with a tested, ingredient-specific factor instead of a generic table.
All-purpose flour cups to grams
Spooned & leveled · rounded for kitchen use
| Cups | Grams | Ounces |
|---|---|---|
| ¼ cup | 30 g | 1.058 oz |
| ⅓ cup | 40 g | 1.411 oz |
| ½ cup | 60 g | 2.116 oz |
| ⅔ cup | 80 g | 2.822 oz |
| ¾ cup | 90 g | 3.175 oz |
| 1 cup | 120 g | 4.233 oz |
| 1 ½ cups | 180 g | 6.349 oz |
| 2 cups | 240 g | 8.466 oz |
| 3 cups | 360 g | 12.7 oz |
Exact factor details
- Exact factor
- 1 cup = 120 g (spooned & leveled)
- Significant digits
- 3 significant figures for table display
- Data source
- USDA FoodData Central · spooned-and-leveled convention
Why flour conversions vary
A cup of flour is the least reliable cup in the kitchen. Scooping the cup into the bag packs in up to 150 g, while spooning flour into the cup and leveling it gives a stable 120 g. Professional bakers weigh flour for exactly this reason: a 25-gram error is invisible in a stew and decisive in a sponge cake.
Our factor for flour — 120 g per US cup — comes from USDA FoodData Central · spooned-and-leveled convention. Weighing beats measuring cups for repeatability: a scale gives the same result every time regardless of how the ingredient settled, and it scales recipes cleanly. Note that a US cup (236.6 ml) and a metric cup (250 ml) are not the same; recipes from outside North America may assume the metric size, which shifts every weight by about five percent.
The table below lists the amounts bakers actually reach for — quarters, thirds, and halves of a cup through three full cups — computed directly from the factor above. The converter handles any other amount instantly and uses the exact same number, so the quick reference and the live result can never drift apart.
Frequently asked questions
How much does 1 cup of flour weigh?
One US cup of all-purpose flour weighs 120 g (spooned & leveled). This comes from USDA FoodData Central · spooned-and-leveled convention.
Why do some recipes list a different weight for flour?
Measuring conventions and brands differ, and packing changes the weight. We state our convention openly; when a recipe names its own gram value, follow that one for best results.
Should I measure flour by cups or by weight?
Weight, whenever the recipe allows. Fluff the flour, spoon it into the cup, then level it with a straight edge — never dip the cup into the bag.