gallons (US) to liters Converter
Type a value in gallons (US) and get the answer in liters instantly — or convert the other way. The conversion uses the exact relationship 1 gallons (US) = 3.78541 liters, the same formula used in textbooks and engineering references.
Convert US gallons to liters for fuel economy comparisons, recipes and aquarium sizes. One US gallon is exactly 3.785411784 liters — multiply and done.
How to use
- Type your value into the gallons (US) box — the liters result updates as you type.
- To go the other direction, type into the liters box instead and read the gallons (US) result.
- Copy the result with one tap, or scan the reference table below for common values.
Frequently asked questions
How do you convert gallons (US) to liters?
Multiply the number of gallons (US) by 3.78541. For example, 10 gallons (US) = 37.8541 liters. The converter above does this for you and shows more decimal places than you will ever need.
How many liters are in one gallons (US)?
Exactly 3.78541 liters. This is a fixed definition, not an approximation, so the conversion is exact at any scale.
Is this converter accurate for professional use?
Yes — it uses full double-precision arithmetic and the official gallons (US)-to-liters factor, so results are reliable for schoolwork, cooking, fitness, travel and technical work.
Can I convert liters back to gallons (US)?
Yes. The converter is two-way: just type in the second box and the first box updates instantly with the reverse conversion.