When measuring flour, it's important to use the correct method to ensure accuracy. The standard weight of one cup of all-purpose flour is approximately 4.25 ounces or 120 grams. However, the weight may vary depending on factors such as the type of flour, the humidity in the environment, and the method of measuring. Spooning the flour into the measuring cup and then leveling it off with a straight edge is the most accurate method. Scooping the flour directly from the bag or container can compress it, leading to an incorrect measurement.