Convert Cups to Grams

Why a Cup Isn't Always a Cup

Unlike most unit conversions, cups to grams has no single conversion factor. A cup is a volume measurement (236.6 mL in the US), but grams measure weight. The bridge between them is density, and density varies wildly by ingredient.

Consider what happens when you scoop one level US cup of these common ingredients:

• All-purpose flour: ~120 g
• Granulated sugar: ~200 g
• Brown sugar (packed): ~220 g
• Honey: ~340 g
• Butter: ~227 g
• Rolled oats: ~90 g
• Cocoa powder: ~85 g

That is nearly a 4x difference between the lightest and heaviest ingredients. This is exactly why our converter includes an ingredient selector. Picking "flour" vs "sugar" gives you a completely different gram value for the same cup measurement.

The Spoon-and-Level Technique

Even with a correct density value, how you fill the cup matters. Scooping directly from the bag compresses flour, and you can end up with 150 g or more in a single cup instead of the expected 120 g. Professional bakers use the spoon-and-level method: spoon the flour into the measuring cup, then level it off with a straight edge. This technique gives consistent results that align with the USDA reference densities our converter uses.

For sticky ingredients like honey or peanut butter, spray the cup with cooking oil first so the ingredient slides out cleanly. Otherwise you lose a significant amount stuck to the sides, throwing off your measurement.

Where Our Data Comes From

The gram weights in this converter come from the USDA FoodData Central database, which measures actual ingredient densities under standardized conditions. We cross-reference with King Arthur Baking's published flour weights and the Rose Levy Beranbaum baking references for specialty ingredients. When sources disagree, we use the USDA value as the baseline.

When to Ditch Cups Entirely

If you bake regularly, a $15 kitchen scale will change your results overnight. Weight measurements eliminate the guesswork of how tightly you packed the cup, whether you used the dip-and-sweep or spoon-and-level method, and whether your "tablespoon" was actually level. Every professional bakery on earth measures by weight. For casual cooking (soups, stews, sauces), cups work fine since a 10% variation in broth or chopped vegetables rarely matters. But for anything with flour, sugar, or leavening agents where ratios are critical, grams win every time.

Check our cooking unit conversions guide for a full ingredient density table covering 60+ common baking and cooking ingredients.