Please note that, fluid ounce is a volume unit and ounce is a mass/weight unit in the imperial and US customary measurement systems. The gallon capacity can only be converted into fluid ounces.
How many gallons are there in a fluid ounce?
1 US fluid ounce is 1/128 of a US fluid gallon (there is 0.0078125 US fluid gallon in a US fluid ounce). 1 Imperial fluid ounce is 1/160 of an imperial gallon (there is 0.00625 imperial gallon in an imperial fluid ounce).
How to convert from fluid ounces to gallons?
To convert from fluid ounces to gallons, multiply the number of fluid ounces "x" by 0.0078125 for US fluid gallon and multiply by 0.00625 for the imperial gallon (UK).
For example, to find out how many gallons there are in 64 US fluid ounces, multiply 64 by 0.0078125, that makes 0.5 (1/2) gallons in 64 US fluid ounces.
You may also use this volume units conversion tool to convert between US, imperial gallons and fluid ounces.
What is a fluid ounce (fl oz)?
Fluid ounce is an imperial and US customary measurement system volume unit. 1 US fluid ounce equals to 29.5735 mL and 1 imperial (UK) fluid ounce equals to 28.4131 mL. The abbreviation is "fl oz".
What is a gallon?
Gallon is an imperial and US customary measurement system volume unit. 1 US fluid gallon is defined as 231 cubic inches and 1 imperial gallon is 277.4 cubic inches. The abbreviation is "gal".
The list for your reference:
1 US Fluid Ounce = 0.0078125 (1/128) US Fluid Gallon
1 Imperial Fluid Ounce = 0.00625 Imperial Gallon (UK)
For US Fluid Ounces to Gallons:
32 fl oz = 1/4 gal
64 fl oz = 1/2 gal
96 fl oz = 3/4 gal
128 fl oz = 1 gal
192 fl oz = 3/2 gal
256 fl oz = 2 gal
For Imperial Ounces to Gallons:
40 imp. fl oz = 1/4 gal
80 imp. fl oz = 1/2 gal
120 imp. fl oz = 3/4 gal
160 imp. fl oz = 1 gal
240 imp. fl oz = 3/2 gal
320 imp. fl oz = 2 gal