Fluid ounce

A fluid ounce (abbreviated fl oz, fl. oz. or oz. fl.) is a unit of volume in both the imperial and the US customary systems. It is common to refer to the unit simply as an ounce, especially in cases where no confusion with the unit of mass is likely to occur.

Definitions

 * Imperial fluid ounce
 * The imperial fluid ounce is $1/undefined$ of an imperial gallon making it very nearly the volume occupied by one avoirdupois ounce of water.


 * height=120%|1 imperial fluid ounce
 * align=right|1/160||imperial gallons
 * align=right|1/20||imperial pints
 * align=right|1/5||imperial gills
 * align=right|8||imperial fluid drams
 * align=right|28.4130625||millilitres (exactly)
 * align=right|1.733871455||cubic inches
 * align=right|0.960759940||U.S. fluid ounces
 * }
 * align=right|1/5||imperial gills
 * align=right|8||imperial fluid drams
 * align=right|28.4130625||millilitres (exactly)
 * align=right|1.733871455||cubic inches
 * align=right|0.960759940||U.S. fluid ounces
 * }
 * align=right|28.4130625||millilitres (exactly)
 * align=right|1.733871455||cubic inches
 * align=right|0.960759940||U.S. fluid ounces
 * }
 * align=right|0.960759940||U.S. fluid ounces
 * }
 * align=right|0.960759940||U.S. fluid ounces
 * }


 * U.S. customary fluid ounce
 * The U.S. customary fluid ounce is defined to be $1/undefined$ of a U.S. gallon. This volume of cool, pure water weighs about 1.04 avoirdupois ounces (29.5 g).




 * 1 U.S. fluid ounce ||=
 * align=right|1/128||U.S. gallon
 * align=right|1/16||U.S. pints
 * align=right|1/4||U.S. gills
 * align=right|8||U.S. fluid drams
 * align=right|1.8046875||cubic inches (exactly)
 * align=right|29.5735295625||millilitres (exactly)
 * align=right|1.040842731||imperial fluid ounces
 * }
 * align=right|8||U.S. fluid drams
 * align=right|1.8046875||cubic inches (exactly)
 * align=right|29.5735295625||millilitres (exactly)
 * align=right|1.040842731||imperial fluid ounces
 * }
 * align=right|1.8046875||cubic inches (exactly)
 * align=right|29.5735295625||millilitres (exactly)
 * align=right|1.040842731||imperial fluid ounces
 * }
 * align=right|1.040842731||imperial fluid ounces
 * }
 * align=right|1.040842731||imperial fluid ounces
 * }


 * U.S. food labelling fluid ounce
 * U.S. regulation 21 CFR 101.9(b)(5)(viii) also defines a fluid ounce as exactly 30 millilitres, but this is for use in nutrition labelling only. This is not meant to concur with the customary US definition exactly but is a common source of confusion.


 * 30 millilitres ||≈
 * align=right|1.055852392||imperial fluid ounces
 * align=right|1.014420681||U.S. customary fluid ounces
 * align=right|1.830712323||cubic inches
 * }
 * align=right|1.014420681||U.S. customary fluid ounces
 * align=right|1.830712323||cubic inches
 * }
 * align=right|1.830712323||cubic inches
 * }


 * Other Useful Conversions

Given the definitions above, we can calculate how many US fluid ounces are in one liter:

1/29.5735295625 * 1000 = 33.8140

There are thus about 34 fluid ounces in one liter.

References and notes
Fluid ounce Onza líquida Once liquide 플루이드 온스 Oncia liquida Fluid ounce 液量オンス Onça (capacidade) Fluid ounce