There are approximately 2.6 ounces in one-third cup. Convert cup measurements to ounces by multiplying the cup measurement by 8, which is the number of fluid ounces in 1 cup. Other common conversions to ounces are one-third to 0.33, one-half to 0.5, one-fourth to 0.25 and one-eighth to 0.125.
The actual amount of ounces in a cup varies depending on what is being measured. Dry ingredients, such as flour or sugar, tend to weigh less per ounce than solids and heavier liquids, such as butter or honey. For example, one-third cup of brown sugar equals 2.58 ounces, while one-third cup of honey equals 4 ounces. One-third cup of all-purpose flour is equal to 1.5 ounces.