fluid ounce

noun

1. a measure of capacity equal to 1/16 (0.0625) pint (29.6 milliliters) in the U.S., and equal to 1/20 (0.05) of an imperial pint (28.4 milliliters) in Great Britain. fl. oz; f

fluid ounce

noun

1. a unit of capacity equal to the volume of one avoirdupois ounce of distilled water at 62°F: there are twenty fluid ounces in an Imperial pint and sixteen in a US pint

fluid ounce

1. A unit of liquid volume or capacity in the US Customary System equal to 1/16 of a pint (29.57 milliliters).

2. See Table at measurement

Word History and Origins

Origin of fluid ounce¹

First recorded in 1880–85

When To Use

What does fluid ounce mean?

A fluid ounce is a unit used in the measurement of the volume of liquids.It is commonly abbreviated as fl. oz. (or fl oz), which can mean a singular fluid ounce, or, more commonly, the plural fluid ounces.An ounce is a unit used in the measurement of weight. (Both ounce and ounces can be abbreviated as oz.) A fluid ounce is used to measure volume (capacity), not weight—specifically, the volume of a fluid (liquid). In everyday conversation, the word ounces is often used instead of saying fluid ounces, as in I just drank 16 ounces of that energy drink. The abbreviation oz. is sometimes used in this way, as in a 20 oz. bottle of water. You’ll often see the abbreviation fl. oz. on the labels of containers that contain liquid or some other kind of non-solid, such as a can of soda or a bottle of moisturizer, to indicate how much stuff the container contains. It is also seen in recipes.Fluid ounces are used in the United States Customary System and the British Imperial System of measurement.In the Customary System, there are 8 fluid ounces in a cup and 16 fluid ounces in a pint. There are 20 fluid ounces in an Imperial pint.A fluid ounce is equal to 29.57 milliliters (1 milliliter is equivalent to 0.033815 of a fluid ounce.)Example: Standard soft drink cans contain 12 fluid ounces, but they also sell 8 oz. cans.