Cups of Butter to Grams

The actual conversion

One US cup of butter weighs almost exactly 227 grams. This is one of the cleanest cooking conversions in the kitchen because butter is sold in standardized sticks: in the United States, a stick of butter is 4 ounces (113.4 g), and 2 sticks make 1 cup. Half a cup is 1 stick (113 g); a quarter cup is half a stick (57 g); a tablespoon of butter is one-eighth of a stick (14.2 g). The math is unusually clean.

The 227 g per cup figure assumes butter is at refrigerator temperature, not melted. Softened butter occupies slightly more volume per gram (the butter has incorporated a small amount of air during mixing) but not enough to matter for a recipe.

Why butter measurements are reliable

Unlike flour, where the conversion depends entirely on technique, butter is a uniform solid at refrigerator temperature with a consistent density of about 911 kg/m³ — very close to but just below the density of water. The volume of butter in a measuring cup is reliably the same every time you measure it, as long as you press it down without leaving large air gaps.

The American stick-of-butter convention is genuinely useful for this reason. Sticks are wrapped with tablespoon and ounce markings printed on the wrapper, so you can cut off "4 tablespoons" without using any measuring tools at all. This is a meaningful difference from European butter, which is usually sold in unmarked 250 g blocks (a metric block of butter is 1.1 cups, or 8 oz 4 tsp in US measure — slightly more than a US half-pound stick).

Salted vs unsalted: same weight, different recipe

The weight of butter doesn't change whether it's salted or unsalted. A cup of salted butter and a cup of unsalted butter both weigh 227 g. What changes is the salt content: salted butter typically contains about 1.5% salt by weight, so a cup of salted butter has about 3.4 g of salt baked in. If you substitute salted for unsalted in a recipe that already adds salt, you'll oversalt the final dish. Most professional baking recipes call for unsalted butter specifically so the recipe writer can control salt exactly.

European butter and the 80% question

European butter has more butterfat than American butter — typically 82–85% versus 80%. The weight per cup is essentially the same (the higher butterfat is a slight density change but well within measurement noise), but the higher fat content means European butter behaves differently in baking. Croissants and laminated doughs made with European butter laminate more cleanly because the butter stays solid at slightly higher temperatures during the folding process. American butter works fine for most recipes; European is worth seeking out for pastry where the butter is the star.

Common mistakes

The most frequent error is melting butter before measuring it. A cup of melted butter is about the same weight as a cup of solid butter (the volume changes by only 1–2% on melting), so by-volume measurement is fine in either state. But many recipes call for "1 cup butter, melted" — meaning measure first, then melt. If you melt first and then measure, you might measure slightly differently because liquid butter is harder to gauge in a dry measuring cup.

Margarine substitutes are sometimes treated as equivalent to butter by weight, which works for cookies and quick breads but fails for laminated pastry. Margarine has different fat composition and water content, both of which affect how it behaves in layered doughs. Stick with butter for croissants and puff pastry.