How many ounces [US, liquid] in 400 gallons [US, liquid]?

A gallon [US, liquid] is a unit of volume commonly used in the United States to measure liquids. One US gallon is defined as 3.785 liters.

Gallons are commonly used to measure the volume of liquids in the United States, particularly to measure the volume of

Dairy products are often measured in gallons in the United States.

Pools and aquariums are often measured in gallons.

Bottles and cans of milk, icecream, juice, soda, etc. may be labeled with their volume in gallons.

Some recipes, especially in older cookbooks, may call for measurements in gallons.

An ounce is a unit of mass commonly used in the United States Customary System and the British Imperial System of measurement. One ounce is equal to 28.3495 grams in the International System of Units (SI). The ounce is abbreviated as "oz".

Ounces are commonly used to measure the weight of various objects, such as

Food ingredients: Small amounts of ingredients such as spices, herbs, and flavorings are often measured in ounces.
The weight of liquids such as coffee, tea, or wine may be expressed in ounces.
The weight of precious metals, such as gold or silver, used in jewelry is often expressed in ounces.
The weight of equipment such as baseballs, softballs, and golf balls is often expressed in ounces.
In some contexts, body weight may also be expressed in ounces, especially for very young or small animals.