The United States uses a system of measurement that varies from most of the rest of the world. The United States uses units and standards while the rest of the world uses the metric system. It is important to understand how to convert the units and standards to the metric system. A liquid or solid which would be considered 3/4 cup equals 0.75 cups. After conversion, 0.75 cups is equivalent to 6 ounces in the metric system.