Gallons to Liters Fuel Converter
Convert fuel volumes between US gallons, Imperial gallons, and liters. Enter values for instant results with step-by-step formulas.
Reviewed by Manoj Kumar, Mathematics Educator
Formula
Liters = US Gallons x 3.785411784 | Liters = Imperial Gallons x 4.54609
US gallons are converted to liters by multiplying by 3.785411784, and Imperial gallons by multiplying by 4.54609. These precise conversion factors are defined by international agreement and used worldwide for fuel volume standardization.
Worked Examples
Example 1: Converting a Full SUV Tank from US Gallons to Liters
Problem:An SUV has an 18 US gallon fuel tank. How many liters does it hold, and what is the equivalent in Imperial gallons?
Solution:Liters = US Gallons x 3.785411784\nLiters = 18 x 3.785411784\nLiters = 68.137 liters\n\nImperial Gallons = Liters / 4.54609\nImperial Gallons = 68.137 / 4.54609\nImperial Gallons = 14.989 Imperial gallons
Result:18 US gallons = 68.14 liters = 14.99 Imperial gallons
Example 2: Converting European Fuel Purchase to US Gallons
Problem:A traveler in France fills up with 50 liters of diesel. How many US gallons and Imperial gallons did they purchase?
Solution:US Gallons = Liters / 3.785411784\nUS Gallons = 50 / 3.785411784\nUS Gallons = 13.209 US gallons\n\nImperial Gallons = Liters / 4.54609\nImperial Gallons = 50 / 4.54609\nImperial Gallons = 11.00 Imperial gallons
Result:50 liters = 13.21 US gallons = 11.00 Imperial gallons
Frequently Asked Questions
How many liters are in one US gallon of fuel?
One US gallon contains exactly 3.785411784 liters. This conversion factor is defined precisely by the international yard and pound agreement of 1959, which established the relationship between customary and metric units. For quick mental math, you can approximate this as 3.8 liters per US gallon, which gives results accurate to within about half a percent. When filling up a car with a 15-gallon tank, you would need approximately 56.8 liters of fuel. This conversion is essential for international travelers who rent cars, as fuel pumps in most countries outside the United States display prices and volumes in liters rather than gallons.
Why do different countries use different fuel volume measurements?
The United States retained the US gallon from its colonial-era measurement system, while the United Kingdom originally used the Imperial gallon before transitioning to liters with metrication in the 1990s. Most countries worldwide adopted the metric system and sell fuel in liters. Canada switched from Imperial gallons to liters in 1979 as part of its metrication program. The persistence of gallons in the US reflects the broader reluctance to adopt the metric system for everyday measurements. Some countries in the Caribbean and parts of Central America also still use US gallons due to American economic influence. Understanding these differences is critical for international trade in petroleum products.
How do I convert fuel economy between miles per gallon and liters per 100 kilometers?
To convert from miles per US gallon to liters per 100 kilometers, divide 235.215 by the MPG value. For example, 30 MPG equals 235.215 divided by 30, which gives 7.84 liters per 100 km. For Imperial MPG, divide 282.481 by the MPG value instead. The conversion is inverse, meaning higher MPG corresponds to lower L/100km. This inverse relationship can be counterintuitive because a 10 MPG improvement from 20 to 30 MPG saves more fuel than an improvement from 30 to 40 MPG. The liters per 100 km metric is used throughout Europe, Australia, and most other countries that have adopted the metric system for fuel economy ratings.
What are typical fuel tank sizes in gallons and liters for common vehicles?
Compact cars typically have fuel tanks of 10 to 13 US gallons or about 38 to 49 liters. Mid-size sedans hold 14 to 16 US gallons or approximately 53 to 61 liters. Full-size SUVs carry 18 to 26 US gallons or about 68 to 98 liters. Pickup trucks range from 24 to 36 US gallons or roughly 91 to 136 liters, with some heavy-duty models having even larger tanks. Motorcycles have small tanks of 3 to 6 US gallons or about 11 to 23 liters. Commercial semi-trucks carry 120 to 300 US gallons or approximately 454 to 1136 liters in dual saddle tanks. Electric vehicles with range extenders often have much smaller fuel tanks.
References
Reviewed by Manoj Kumar, Mathematics Educator · Editorial policy