US liquid gallons
A US liquid gallon is a volume measurement used in the United States for liquids such as water, gasoline, and milk. One US liquid gallon is about 3.78541 liters. A standard bathtub is about 80 gallons of water and a car gas tank can hold anywhere between 12 and 20 gallons of gas.
UK fluid ounces
A UK fluid ounce is about 28.41 milliliters, a little smaller than the US fluid ounce of about 29.57 milliliters. So 1 US fluid ounce is about 1.04 UK fluid ounces.