How many fluid ounces are in a gallon

In the US, there is 128 fluid ounces in a gallon

In the UK, there is 160 fluid ounces in a gallon

1 gallon = 128 fluid ounces

To convert gallons to fluid ounces you do the following

amount of gallons * 128 = amount of fluid ounce in the gallons

Example:-

3 gallons = ? fluid ounces

3 * 128 = 384

3 gallons = 384 fluid ounces