Gallons to Liters Converter
Converting gallons to liters is simple once you know which type of gallon you are using. For a US liquid gallon, multiply the number of gallons by 3.785411784. Therefore, 1 US gallon equals approximately 3.785 liters, while 5 gallons equal about 18.927 liters.
Use the calculator below when you need a quick and accurate conversion. This page uses the US liquid gallon as the default because it is the gallon commonly used in the United States. However, an Imperial gallon is larger, so it requires a different conversion factor.
Convert Gallons to Liters Instantly
Need an answer without doing the calculation yourself? Enter the number of US gallons into the converter below and select Convert gal to L. The calculator will instantly show the equivalent volume in liters.
The calculator uses the standard relationship 1 US gallon = 3.785411784 liters. As a result, it is suitable for everyday conversions as well as situations where greater numerical accuracy is useful.
Important: US gallons and Imperial gallons are not the same size. The calculator below converts US liquid gallons to liters. If you are working with UK Imperial gallons, use the Imperial conversion explained further down the page.
How to Convert Gallons to Liters
The gallons to liters formula for US liquid gallons is:
Liters = Gallons × 3.785411784
For example, suppose you have 5 US gallons:
5 × 3.785411784 = 18.92705892 liters
Therefore, 5 gallons = approximately 18.927 liters.
For most everyday purposes, rounding the result to two or three decimal places is more than sufficient. However, keeping additional decimal places can be useful in technical calculations or when converting larger quantities.
Quick estimation
If you only need a rough answer, you can multiply the number of gallons by 3.8. For instance, 10 gallons would be roughly 38 liters.
However, the full conversion factor provides a more accurate result:
10 US gallons = 37.85411784 liters
Therefore, use the calculator whenever precision matters.
US Gallons vs Imperial Gallons
One of the most important details when converting gallons to liters is identifying which gallon is being used.
A US liquid gallon equals:
1 US gallon = 3.785411784 liters
An Imperial gallon, historically used in the United Kingdom and still encountered in some contexts, equals:
1 Imperial gallon = 4.54609 liters
Consequently, an Imperial gallon is about 20% larger than a US gallon.
For example:
10 US gallons = 37.854 liters
However:
10 Imperial gallons = 45.461 liters
That difference is large enough to matter when dealing with fuel, water tanks, industrial liquids, or other substantial volumes. Therefore, always check which gallon standard is being used before making the conversion.
NIST likewise lists the US gallon as approximately 3.785412 L and the Imperial gallon as 4.54609 L.
What Is a Gallon?
A gallon is a unit of volume rather than weight. In the United States, the US liquid gallon is widely used for fuels, beverages, water, and other liquids.
One US liquid gallon contains exactly 231 cubic inches and 128 US fluid ounces. In metric terms, it corresponds to 3.785411784 liters.
Because gallons are not part of the metric system, conversions are often necessary when American measurements are compared with specifications from countries that use liters.
What Is a Liter?
A liter, symbol L, is a metric unit of volume. One liter is equal to 1,000 milliliters or one cubic decimeter.
Liters are widely used internationally for measuring liquids, including beverages, fuel, household products, water, and industrial fluids.
Therefore, converting gallons into liters is especially useful when US measurements need to be understood in a metric context.
Why Is Gallons to Liters Conversion Important?
The need to convert gallons to liters often appears when measurements move between the United States and countries using the metric system.
For example, an American product specification may describe a container as holding 20 gallons. However, a customer accustomed to metric measurements will probably find 75.708 liters much easier to understand.
The same issue appears in vehicle specifications. A fuel tank may be listed in gallons on a US website but in liters on an international website. Converting between the units makes those specifications directly comparable.
Moreover, accurate conversions can prevent misunderstandings when buying containers, planning water storage, comparing equipment, or calculating liquid capacity.
Where Are Gallons to Liters Conversions Used Most Often?
Fuel and automotive measurements
Fuel capacity is one of the most common examples. Vehicles sold in the United States may have tank sizes stated in gallons, whereas vehicle specifications elsewhere usually use liters.
For instance, a 15-gallon fuel tank holds approximately 56.781 liters.
Therefore, converting the units can make international vehicle comparisons much easier.
Water tanks, aquariums and pools
Aquariums and storage tanks are also frequently advertised in gallons, particularly by US manufacturers.
A 20-gallon aquarium, for example, has a nominal volume of approximately 75.708 liters. Meanwhile, a 50-gallon tank corresponds to approximately 189.271 liters.
Knowing both measurements can be useful when selecting pumps, filters, chemicals, or other equipment.
Food and beverage production
Large-volume food and beverage measurements may also be given in gallons. This is particularly common for commercial quantities rather than ordinary household recipes.
Therefore, businesses working with international recipes, production specifications, or imported equipment may need to convert the measurement into liters.
Industrial and commercial containers
Buckets, drums, reservoirs, sprayers, and other containers may also be rated in gallons.
Because international product specifications often use metric units, converting gallons to liters provides a simple way to compare capacities accurately before purchasing equipment.
How Accurate Should the Conversion Be?
The level of precision you need depends on the situation.
For normal everyday use, two decimal places are generally enough. Therefore, you could write:
25 gallons ≈ 94.64 liters
For product specifications or more precise calculations, three or more decimal places may be useful:
25 gallons = 94.635 liters
However, unnecessary decimal places can make a simple result harder to read. For that reason, our calculator keeps sufficient precision while still presenting the answer in a practical format.
The underlying calculation uses 3.785411784 liters per US gallon, so rounding only occurs when the result is displayed.
Gallons to Liters Conversion Table
The following gallons to liters conversion table uses US liquid gallons and the factor 1 gal = 3.785411784 L.
| US Gallons (gal) | Liters (L) |
|---|---|
| 1 | 3.785 |
| 10 | 37.854 |
| 20 | 75.708 |
| 30 | 113.562 |
| 40 | 151.416 |
| 50 | 189.271 |
| 60 | 227.125 |
| 70 | 264.979 |
| 80 | 302.833 |
| 90 | 340.687 |
| 100 | 378.541 |
These values are rounded to three decimal places. Therefore, use the calculator above when you need another value or more decimal precision.
Frequently Asked Questions
- How many liters are in one gallon?
One US liquid gallon equals exactly 3.785411784 liters based on the conversion factor used by NIST. For everyday calculations, this is usually rounded to 3.785 liters.
- How do I convert gallons to liters?
Multiply the number of US gallons by 3.785411784.
For example:
8 gallons × 3.785411784 = 30.283294272 liters
Therefore, 8 US gallons equal approximately 30.283 liters. - How many liters are in 5 gallons?
Five US gallons equal approximately 18.927 liters.
The calculation is:
5 × 3.785411784 = 18.92705892 L - How many liters are in 10 gallons?
Ten US gallons equal approximately 37.854 liters.
- How many liters are in 20 gallons?
Twenty US gallons equal approximately 75.708 liters.
- How many liters are in 100 gallons?
One hundred US gallons equal approximately 378.541 liters.
- Is a US gallon the same as an Imperial gallon?
No. A US liquid gallon equals 3.785411784 liters, whereas an Imperial gallon equals 4.54609 liters.
Therefore, you should always identify the gallon type before converting a measurement. - Is a gallon larger than a liter?
Yes. One US gallon contains approximately 3.785 liters, so a gallon is considerably larger than one liter.
- What is the abbreviation for gallons and liters?
The common abbreviation for gallon is gal, while the standard symbol for liter is L.
Final Word
Converting gallons to liters requires only one multiplication: multiply US gallons by 3.785411784. However, remember that US and Imperial gallons have different volumes.
For the fastest result, enter your measurement into the converter above. You can also use the conversion table for common values from 1 to 100 gallons.
