The US gallon (gal) is an imperial volume unit equal to exactly 3.7854 liters, the standard measurement for fuel, milk, and paint in the United States. Gasoline prices at American pumps are always quoted per gallon, and US vehicle fuel efficiency is measured in miles per gallon. One US gallon equals 4 US quarts or 8 US pints.

The US fluid ounce (fl oz) is a volume unit equal to approximately 29.574 milliliters, used to label beverages, cosmetics, and personal care products in the United States. Beverage cans, shampoo bottles, and skincare serums all display their contents in fluid ounces for American consumers. One fluid ounce equals exactly 1/128 of a US gallon or roughly 2 tablespoons.