Convert from Teaspoon [UK] to fifth

Unit Definition (Teaspoon [UK])
The teaspoon is a unit of volume used in food recipes. In Britain, a traditional teaspoonful in the kitchen was equal to 1/8 Imperial fluid ounce or approximately 3.55 milliliters, but the medical teaspoonful was usually 5 milliliters.

Unit Definition (fifth)
The fifth is a traditional U.S. unit of liquid volume equal to 4/5 quart, which is the same as 1/5 gallon. The fifth contains exactly 46.2 cubic inches, or about 757.084 milliliters. This unit is an American version of the traditional bottle.