How many litres are in a gallon? Though the answer for this one may seem like a simple and brief one, one should be aware that there are other types of gallons one need to consider while answering it. Some might get confused and even argue that litres and gallons are the same because both terms are used for measuring liquids. But it is not the same. The value of a gallon varies from country to country. Don’t get confused. It is simple but with slight variations. If you want to know how many litres are in a gallon and its other types, keep on reading this article. But before knowing how many litres in 1 gallon, it is best to define both terms to get a clear idea.

**1. What are litres?**

A litre is defined to be a **metric unit of volume that is equal to a thousand cubic centimetres** or one cubic decimetre. The Museum of Arts and Crafts in Paris shows that the unit litre was first called *cadil*. In 1795, the term litre with the definition of one cubic decimetre was introduced in France as one of the new republican units of measurement.

In 1879, CGPM, a standard body that defines **SI adopted a litre definition with the symbol l**. Later in 1979, the symbol for litre was changed back to **L**. From 1901 to 1964, litre was defined as the volume of one kilogram of pure water at standard pressure and maximum density. (Also read What are the 6 Layers of the Earth?)

**2. What are Gallons?**

There were many definitions and redefinitions for a gallon. Currently, there is one definition in the imperial system and two in the US system. Must read the article on how many cups are in 8 ounces?

- The
**imperial gallon**is defined as the**amount equal to 4.546 cubic decimetres**. - This gallon is used by several commonwealth countries. Till 1976, this gallon was
**defined as 10 pounds of the volume of water**at 16.67 C. - The other type of gallon that is predominantly used is the US gallon is the
**type of liquid and dry**. Legally, a liquid gallon or simply gallon is defined as 3.785 litres or 231 cubic inches. The dry gallon is not used much in commerce and is defined to be equal to 4.404 litres or 268.8025 cubic inches. - One of the big differences between a litre and a gallon is that a
**gallon is a larger quantity of litres**while litres are commonly used as a unit of measurement. (See How many gallons of gas are in a barrel?)

**3. How did the Word Gallon Originate?**

Though the origin of the word is a little vague, it closely originates from the old northern french word, **Galon meaning liquid measure.** It was used to measure wine and beer in England. As a result, it gave birth to the terms wine gallon, ale gallon, and the imperial gallon. The next segment will tell you how many litres are in a gallon. (See When Were Numbers invented?)

**4. Which Countries use Gallons for the Measurement of Liquid?**

The** imperial gallon is used** and is the standard unit for petroleum in ten countries which are,

- The British Virgin Islands, Cayman Islands,
- Montserrat, Antigua and Barbuda, Dominica,
- Grenada, St Christopher, Nevis,
- St Vincent and Grenadines,
- Saint Lucia.

Apart from the USA, the petrol is **sold in US gallons** in the following countries,

- Colombia, Dominican Republic,
- Ecuador, Haiti,
- Liberia, Nicaragua, Peru, Belize,
- Palau, Marshall Islands, etc

**The Bahamas, Turks, and Caicos Islands use both** imperial gallon and US gallon. (Also read How many Minutes are there in a Year?)

**5. How many Litres are in 1 Gallon?**

Now that you have an idea about what gallons and litres are, you can derive the solution for your question of how many litres are in a gallon. (See How many 8 ounces are there in a gallon?)

- Since both are measurements of volume, you can convert the values from one to another. One must be very
**careful while making the conversion.**Because if you take the value of the wrong gallon, the measurement will get wrong. - If you are considering
**an imperial gallon, then there are 4.5 litres in a gallon,**i.e 1 imperial gallon = 4.5 litres - If it is in the case of a
**US gallon, it contains approximately 3.78 litres,**i.e 1 US gallon = 3.78 litres. (See How many cups are there in a gallon?)

**6. What are the Facts about Gallons?**

Some more facts about gallons are,

- The
**human body consists of 1.2 to 1.5 gallons of blood**and is approximately equal to 10 per cent of body weight. -
**Earth is filled with more than 326 million trillion gallons**and is 3 per cent of the whole earth. - Approximately, humans need and
**breathe 2000 gallons of air**, equal to filling a swimming pool to life. - The weight of water is equal to 8 pounds of a gallon.
- To grow food for a family of four, you will
**need 6800 gallons of water**. (See What Is Algebra Used For In Real Life?)

Since petrol and all other important commodities are measured in gallons and liquid, one must be aware of the conversion and know the correct answer to the question of how many litres are in a gallon so that you can’t be tricked in any way while buying liquid products. (See What is a Circle Degree Chart?)