The number of grams in 1 cup is determined by the difference between the weight and volume of the substance being measured. For instance, 1 cup of any regular liquid equals approximately 240 grams, while 1 cup of soup containing solid ingredients, such as noodles or vegetables, weighs more.
Ounces, teaspoons, tablespoons and cups are measurements of the volume of substances, while grams measure the weight of a substance. The weight of solids can differ even if substances have the same volume. For instance, 1 cup of flour and 1 cup of white sugar are the same volume, but they are not the same weight. The weight of 1 cup of flour equals 125 grams, while 1 cup of white sugar equals 200 grams.