Cups of Butter to Grams

Butter density vs water density

The most common mistake in butter-to-gram conversions is using the formula "1 cup = 240ml = 240 grams." This formula is correct for water: water has a density of exactly 1 gram per milliliter at normal kitchen temperatures. But butter is not water. Butter is an emulsion of fat, water, and milk solids, with a density of approximately 0.911 grams per milliliter at room temperature, or 20 degrees C / 68 degrees F.

Wait - but the standard conversion says 1 cup butter = 227g. The reason for this discrepancy is that the 227g figure is derived from stick weight: 1 stick = 4 oz = 113.4g, and 2 sticks = 1 cup = 226.8g, rounded to 227g. That is the industry standard for US butter. The density-based calculation gives a slightly different result because cup measurement of butter, especially softened butter, traps small air pockets. For baking purposes, 227g per cup is the correct working value because it is what major US culinary authorities and butter manufacturers use.

US butter vs European butter weight differences

Not all butter weighs the same per cup. Fat content affects density, and different butter types have different fat contents. US standard butter is usually 80% fat and weighs 227g per cup. European-style butter is usually 82-84% fat and weighs about 230-232g per cup. Clarified butter or ghee is almost pure butterfat and weighs about 205g per cup. Whipped butter is the major exception: air is incorporated into the product, lowering the weight to roughly 151g per cup.

The difference between US butter and European butter is small, about 1-2%, and negligible for most recipes. Whipped butter is not negligible. Never substitute whipped butter by volume for regular butter in baking, because the air content can reduce the actual butter amount by about one third. The practical rule is simple: for any recipe measured by cups, use US standard butter at 227g per cup as the baseline. If you are using European butter by weight, the difference is small enough to ignore in all but the most precision-critical applications.

This matters most when you are translating between recipe traditions. A US cookie recipe that says "1 cup butter" usually means two American sticks, so 227g is the intended amount even if your measuring cup is marked close to 240ml. A French or British recipe that lists 225g or 250g is usually written from a scale-first kitchen, where the number on the scale is the source of truth. If you only have cups, the conversion table gives a workable estimate, but if you have a scale, follow the gram amount printed in the recipe. The calculator keeps these two habits separate: cups become grams through the selected butter type, while grams convert back into an approximate cup amount for planning.

Why a scale is more accurate than a measuring cup

Even with the correct grams-per-cup value, measuring butter by volume introduces errors that weighing eliminates. Cold butter can leave small air gaps in a cup, slightly underestimating the true amount. Softened butter can be packed loosely or tightly, creating up to 15-20% variation between measurements. Melted butter is the only state that measures accurately by volume because it self-levels in the cup.

A kitchen scale set to grams removes those variables. For croissants, puff pastry, Danish dough, or any laminated pastry where the butter-to-flour ratio is structural, weighing butter in grams is not optional. It is the difference between proper lamination and a greasy, collapsed result.