Answer:  Use fluid ounces or its abbreviation floz instead of ounces to perform the conversion.

Explanation:  ConvertIt recognizes ounces as a measurement of mass that is compatible with pounds, kilograms, and other measurements of mass.  ConvertIt recognizes fluid ounces as a liquid measurement which is compatible with gallons, teaspoons, and other liquid measurements.

See also: Convert Fluid Volume To Mass/Weight Measurements