How many ounces are in 1 gallon?

128 ounces
1 US fluid gallon = 128 US fluid ounces
One US gallon = 128 fluid ounces.
1 U.S. gallon = 128 fluid ounces

It also depends on which 'gallon' to which you are referring. There is the U.S. liquid gallon (3.79 liters) and the U.S. dry gallon (3.4 liters), and there is the imperial gallon (4.55 liters), which is the unofficial use in the United Kingdom and Ireland, and the semi-official use in Canada .
There are 128 fluid ounces in one gallon.
1 U.S. fluid gallon = 128 fluid ounces
There are 128 ounces in a U.S. fluid gallon.
There are 128 fluid ounces in a U.S. fluid gallon.


There are 8 ounces in a cup, 2 cups make a pint, 2 pints make a quart, four quarts make a gallon.
1 U.S. fluid gallon = 128 fluid ounces