While this question may seem incredibly straightforward, the answer to it is actually not that simple. There are several important variables we need to take into account when attempting to answer this. However, one is more important than the others, and that is whether we are talking about the US gallon or the UK gallon. In the United States, a gallon equals approximately 3.785 liters.
In the United Kingdom, a gallon is 4.546 liters. Other variables we can take into account are whether we are talking about the dry gallon or the fluid gallon, but those are not that important for this topic.
The Liter Explained
If you are from the United States, you are probably constantly confused by the metric system. Similarly, people from other parts of the world might be confused by the imperial system that is used in the US. A liter is a unit used to measure volume in the metric system. This is actually the international standard of measuring things. The exact volume of one liter is equal to one cubic decimeter. This means that the object we are measuring has length, height, and width.
Initially, people defined liters as the volume of 1 kilogram of water at its peak density. We usually use liters to measure the volume of things that change shape and adapt to their containers. It is mostly used to measure liquids, but there are some solids that can be measured using liters as well. These solids can usually be poured between different containers. We can also use liters to measure things like density. This functions well because it is easier to compare the density of the thing we measure to the density of water.
A gallon is also a unit used to measure the volume, mostly of fluids. Gallons are used in the US measuring system and in the British imperial system of measurement. However, there are differences between the two gallons. The Imperial gallon equals 4.546 liters, while the US gallon equals 3.785 liters. Although the majority of the countries on the planet use the metric system, the Imperial gallon is used in Canada, the United Kingdom, and several countries in the Caribbean, like the Bahamas, the British Virgin Islands, and several more.
On the other hand, the US gallon is used not only in the United States but also in Colombia, Belize, Guatemala, Haiti, and Peru, among others. However, the US gallon in these countries is mostly used just for gasoline. The US gallon also has a sub-type called the dry gallon. This type of gallon is used when measuring dried goods. Still, it is not used often.
The Process Of Conversion
Since we use both gallons and liters to measure volume, converting between them is possible and quite simple. Still, you need to be careful of what type of gallons you are using when converting since both have different weights. A lot of people just combine the two and say find the middle ground by saying that a gallon is equal to 4 liters. However, while often an easy way out, this is incorrect.
Basically, the easiest way to convert gallons into liters is by multiplying the number of gallons to the number of liters in a single gallon. Just be sure you are using the correct type of gallons. This means that if you are trying to convert 7 gallons into liters by using the US gallons, you will just multiply that number with 3.785. Or you could just use an online conversion tool, that would be much easier.