One cup of powdered sugar is 4.41 ounces, so there are 3.63 cups in a pound of powdered sugar. The calculation is 16 ounces divided by 4.41 ounces per cup. Sifted powdered sugar is 3.61 ounces per cup, so there are 4.4 cups in one pound of powdered sugar if it is sifted. Contrarily, granulated sugar is 7.1 ounces per cup, and packed brown sugar is 7.75 ounces per cup.
Powdered sugar, or confectioner's sugar, is made by placing granulated sugar in a blender and then running it on pulse speed. Granulated sugar then is turned into a fine powder after a few moments. This method works best for small quantities, such as 1 to 2 cups at a time. Commercially produced powdered sugar also includes corn starch as a thickening agent.
Powdered sugar dissolves quickly in liquids. The finer grain of the sugar makes icing and glazes when mixed with milk, and can be used to make a light topping for all kinds of desserts. Confectioner's sugar can be placed into baked goods that require sugar, such as cookies, cakes, muffins, pies, macaroons and doughnuts.
When making icing, powdered sugar is mixed with butter, milk and vanilla extract. Additional ingredients such as chocolate, peanut butter or lemon add flavor to the base recipe. Confectioner's sugar is gradually added to liquid until the icing thickens to the proper consistency.