Gallon – Definition With Examples
Updated on January 9, 2024
Welcome to the Brighterly Math for Kids guide on gallons! In this comprehensive guide, we will explore the fascinating world of gallons, a unit of measurement that is essential in understanding volume measurements in everyday life. By diving deep into this topic, you’ll gain valuable knowledge and insights that will help you excel in math and beyond. At Brighterly, our goal is to make learning fun, engaging, and accessible for children of all ages.
What Is a Gallon?
A gallon is a unit of measurement for volume, commonly used in the United States and the United Kingdom for liquids such as gasoline, milk, and water. In the U.S., a gallon is equivalent to 128 fluid ounces or 3.78541 liters, while in the U.K., it is equivalent to 160 fluid ounces or 4.54609 liters. The gallon is primarily used in countries that follow the Imperial or U.S. customary systems of measurement. In the metric system, which is used by most countries around the world, the standard unit of volume is the liter. The term “gallon” can be abbreviated as “gal” in both the U.S.
Definitions and Divisions
There are two primary definitions of the gallon: the U.S. liquid gallon and the Imperial gallon. The U.S. liquid gallon, as mentioned earlier, is equal to 128 fluid ounces, or 3.78541 liters. The Imperial gallon, used in the U.K. and other countries that employ the Imperial system of measurement, is equal to 160 fluid ounces, or 4.54609 liters.
A gallon can be divided into smaller units, such as quarts, pints, and cups. In the U.S. system:
 1 gallon = 4 quarts
 1 quart = 2 pints
 1 pint = 2 cups
In the Imperial system:
 1 gallon = 4 quarts
 1 quart = 2 pints
 1 pint = 4 gills
History of Gallon
The history of the gallon can be traced back to the medieval period in England, when it was first introduced as a unit for measuring wine and ale. The word “gallon” is derived from the Old French word “galon,” which referred to a liquid measure. Over time, the gallon was standardized to the presentday Imperial gallon and U.S. liquid gallon. The differences between the two gallons are a result of changes in the systems of measurement used in the U.S. and the U.K.
Uses of Gallon
Gallons are commonly used to measure the volume of liquids, such as gasoline, milk, and water. In the United States, gasoline is sold in gallons at gas stations, and milk is often purchased in gallonsized containers. Gallons are also used to measure the volume of large containers, like swimming pools, and the capacity of appliances, such as washing machines and water heaters.
How to Convert Gallon to Liter?
To convert gallons to liters, you need to use the conversion factor between the two units. For U.S. gallons, the conversion factor is 3.78541, while for Imperial gallons, it is 4.54609. Here’s the formula:
 U.S. gallons to liters: Gallons * 3.78541 = Liters
 Imperial gallons to liters: Gallons * 4.54609 = Liters
Liters to Gallons Formula
To convert liters to gallons, you need to use the inverse conversion factor. For U.S. gallons, the conversion factor is 0.264172, while for Imperial gallons, it is 0.219969. Here’s the formula:
 Liters to U.S. gallons: Liters * 0.264172 = Gallons
 Liters to Imperial gallons: Liters * 0.219969 = Gallons
Gallon to Liter Table
This table provides a quick reference for converting between gallons and liters for both the U.S. liquid gallon and the Imperial gallon:
U.S. Gallons  Liters  Imperial Gallons  Liters 

1  3.78541  1  4.54609 
2  7.57082  2  9.09218 
3  11.35623  3  13.63827 
4  15.14164  4  18.18436 
5  18.92705  5  22.73045 
Solved Examples on Gallon
Here are some solved examples to help you understand the conversion between gallons and liters:

Convert 5 U.S. gallons to liters:
5 (U.S. gallons) * 3.78541 (Liters/U.S. gallon) = 18.92705 liters

Convert 10 liters to U.S. gallons:
10 (Liters) * 0.264172 (U.S. gallons/Liter) = 2.64172 U.S. gallons

Convert 3 Imperial gallons to liters:
3 (Imperial gallons) * 4.54609 (Liters/Imperial gallon) = 13.63827 liters

Convert 15 liters to Imperial gallons:
15 (Liters) * 0.219969 (Imperial gallons/Liter) = 3.299535 Imperial gallons
Practice Problems on Gallon
Try these practice problems to test your understanding of gallon conversions:
 Convert 7 U.S. gallons to liters.
 Convert 25 liters to U.S. gallons.
 Convert 6 Imperial gallons to liters.
 Convert 20 liters to Imperial gallons.
Conclusion
In this article, we covered the definition and history of the gallon, its divisions and uses, and the formulas for converting gallons to liters and vice versa. We also provided solved examples and practice problems to help you understand the conversion process. By learning the different types of gallons and their conversions, you can easily solve realworld problems involving volume measurements.
Frequently Asked Questions on Gallon
What is the difference between a U.S. gallon and an Imperial gallon?
A U.S. gallon is equal to 128 fluid ounces or 3.78541 liters, while an Imperial gallon is equal to 160 fluid ounces or 4.54609 liters. The U.S. gallon is used in the United States, while the Imperial gallon is used in the United Kingdom and countries that follow the Imperial system of measurement.
Why are there different types of gallons?
The differences between the U.S. gallon and the Imperial gallon are a result of the changes in the systems of measurement used in the U.S. and the U.K. over time.
How do I convert gallons to liters and vice versa?
To convert gallons to liters, multiply the number of gallons by the appropriate conversion factor: 3.78541 for U.S. gallons or 4.54609 for Imperial gallons. To convert liters to gallons, multiply the number of liters by the inverse conversion factor: 0.264172 for U.S. gallons or 0.219969 for Imperial gallons.