Fluid ounce

Fluid ounce
A baby bottle in both American and British Imperial fluid ounces
General information
Unit systemImperial units, US customary units
Unit ofVolume
Symbolfl oz
Conversions (imperial)
1 imp fl oz in ...... is equal to ...
   Non-SI units accepted for use with SI   28.4130625 mL
   US customary units   0.96076 US fl oz
Conversions (US)
1 US fl oz in ...... is equal to ...
   Non-SI units   29.5735295625 mL
   Imperial units   1.0408427 imp fl oz

A fluid ounce (abbreviated fl oz, fl. oz. or oz. fl., old forms ℥, fl ℥, f℥, ƒ ℥) is a unit of volume (also called capacity) typically used for measuring liquids. The British Imperial, the United States customary, and the United States food labeling fluid ounce are the three that are still in common use, although various definitions have been used throughout history.

An imperial fluid ounce is 120 of an imperial pint, 1160 of an imperial gallon, or exactly 28.4130625 mL.

A US customary fluid ounce is 116 of a US liquid pint, 1128 of a US gallon, or exactly 29.5735295625 mL, making it about 4.084% larger than the imperial fluid ounce.

A US food labeling fluid ounce is exactly 30 mL.