US Gallons to Litres Converter
Convert US liquid gallons into litres. Use this page when the source quantity is explicitly in US gallons, such as a US water container or label.
Enter a zero or positive amount. Decimal values are supported. Only the displayed result is rounded.
Reference: NIST Guide to the SI, Appendix B.9 (volume conversion factors). The displayed result is rounded; it is a unit conversion, not a measurement of water need.
Formula
L = US gal × 3.785411784
Example: 1 US gal is about 3.785 L.
About these units
NIST distinguishes the US gallon from the Imperial gallon. If your quantity is from a UK/Imperial source, use the Imperial gallons converter instead.
Everyday conversion examples
Use this direction for quantities stated in US liquid gallons, such as many US container labels. Enter a decimal for partial gallons; the result is calculated before its display is rounded.
| US liquid gallons | Litres |
|---|---|
| 0.5 | 1.893 |
| 1 | 3.785 |
| 2 | 7.571 |
| 5 | 18.927 |
Examples are rounded for readability. Use the calculator above for another amount; it keeps the conversion factor until the final display.
How many litres are in one US gallon?
One US liquid gallon is exactly 3.785411784 L by the factor used here; the page displays a rounded result.
Does “gallon” always mean US gallon?
No. The Imperial gallon is larger (4.54609 L). Check the country or label and choose the matching converter.
Source
Conversion factors are based on customary and metric volume relationships documented by the National Institute of Standards and Technology (NIST), Guide to the SI, Appendix B.9. NIST reports rounded factors; this page displays a rounded result.