US fluid ounce (fl oz)
Definition: A US fluid ounce is one 128th of a US gallon, equal to about 29.5735 milliliters.
History/origin: The US fluid ounce came from older English systems and stayed tied to the US gallon after the US and imperial systems diverged.
Current use: US fluid ounces are used on drink cans, nutrition labels, recipes, and personal care products in the United States.


