Thirty-two fluid ounces equal four cups. One cup equals eight fluid ounces. A pint of liquid contains two cups, or 16 fluid ounces. A fluid ounce is a measure of volume and is part of the U.S. Customary System of weights and measures.
The U.S. Customary System, also called the inch-pound system, includes more than 300 different units of measure. Volume is the quantity contained within a three-dimensional space that is held by some type of boundary, such as a container. The volume of a container is generally defined as the capacity it can hold.
Although the United States has officially endorsed the International System of Units, known as the metric system, it is not used in some types of measurements. For instance, football fields are still measured in yards. However, running races in the United States are typically measured in meters.