Cups of Bread Flour to Grams

Why a cup of bread flour doesn't always weigh the same

Volume measurements are forgiving in some ways and brutal in others. A cup of bread flour can vary by 10-20% in weight depending on how it's measured: spooned vs scooped, packed vs loose, sifted vs unsifted. The density figure used here (0.508 g/mL) matches the most common published recipe conventions, but if you're after baking precision, weighing on a kitchen scale is more accurate than measuring by volume.

Sourced from King Arthur Baking: 1 cup = 120g. Spooned and leveled. Same volumetric density as all-purpose in standard cooking references.

Volume vs weight in cooking

The American convention of measuring ingredients by volume (cups, tablespoons, teaspoons) is convenient but introduces variability that doesn't exist in weight-based recipes. Most professional bakers and bakeries weigh ingredients to within a gram because the structure of baked goods depends on precise ingredient ratios. For everyday cooking — soups, sauces, sautés — the volume-to-weight imprecision rarely matters. For baking that depends on rising or texture (cakes, breads, laminated doughs), it matters a lot.

The conversion

Multiplying the volume of bread flour by its density (0.508 g/mL) gives the weight in grams. The calculator at the top of this page does the math automatically; the formula box above shows the resulting linear factor for the specific volume and weight units selected here.