A U.S. pint is equal to 16 U.S. fluid ounces, or 1/8th of a gallon. Thus 4 gallons is equivalent to 32 pints.
A gallon is a unit of volume measurement used widely in the US and a few other countries of the world. The US gallon is usually used for measuring volume of liquid or gaseous substances like gasoline, other types of fuel, etc. One US gallon is equal to roughly 3.79 liters, or 231 cubic inches.
Commonly used for measuring volume for liquid substances used widely around the world, in the countries adopted the Imperial system and the SI. There are a few types of pint, and the pint used in the US and the former colonies of this country is a liquid pint which is equal to approximately 473 mL. There is also a unit known in the US as a dry pint, which is equal to roughly 550 mL.
See pint to gallon conversion chart at Conversion-metric.org and Calculateme.com.
Or, use this US Pints (Liquid) to Gallons calculator to convert between these units of volumes.