There are 128 fluid ounces in one US liquid gallon. This is the standard conversion used in the US customary system
. For reference, the UK (Imperial) gallon is different and contains 160 Imperial fluid ounces, reflecting differences in measurement systems between the US and UK
. So, if you are referring to the US gallon, the answer is:
- 1 US gallon = 128 US fluid ounces.
