US liquid volume converter
How Many Liters in a Gallon?
One US liquid gallon equals 3.785411784 liters. Enter either value to convert gallons and liters instantly.
How to convert gallons to liters
The US liquid gallon is defined from 231 cubic inches. Using the exact international-inch definition gives 3.785411784 liters per US gallon.
liters = US gallons × 3.785411784
US gallons = liters ÷ 3.785411784
1 US liquid gallon = 3.785411784 liters
Example: 5 US gal × 3.785411784 = 18.92705892 L, displayed as 18.9271 L at four decimal places.
Where gallon-to-liter conversion is useful
US product labels and vehicle references may use gallons while most of the world uses liters.
Fuel and vehicle capacity
Compare a tank or refill amount listed in US gallons with a capacity stated in liters.
Aquariums and containers
Translate the labeled volume before choosing equipment, treatments, or fill quantities.
Household and outdoor use
Convert water, paint, storage, and garden-container volumes without mixing US and Imperial gallons.
Common US gallons to liters chart
Liter values are rounded to four decimal places; the calculation uses the full conversion factor.
| US liquid gallons (US gal) | Liters (L) |
|---|---|
| 0.25 | 0.9464 |
| 0.5 | 1.8927 |
| 1 | 3.7854 |
| 2 | 7.5708 |
| 3 | 11.3562 |
| 5 | 18.9271 |
| 10 | 37.8541 |
| 15 | 56.7812 |
| 20 | 75.7082 |
| 25 | 94.6353 |
| 50 | 189.2706 |
| 100 | 378.5412 |
US gallons, Imperial gallons, and rounding
This converter always means the US liquid gallon. An Imperial gallon is larger, so do not use the two gallon definitions interchangeably.
The decimal-place menu affects only the displayed answer. The calculation continues to use 3.785411784 liters per US liquid gallon.
For a measured liquid, preserve the precision of the original container, gauge, or specification instead of assuming every displayed digit is measured accuracy.
Sources and method
The unit constants come from the primary standards below. ToolNeko applies those constants in a browser-only calculation, then rounds only the displayed result.
- NIST Guide to the SI, Appendix B8 Lists the US gallon-to-liter conversion factor used by this page.
- NIST Handbook 44 — Appendix C Provides current general measurement tables and distinguishes liquid-measure units.
Frequently asked questions
How many liters are in a US gallon?
One US liquid gallon equals 3.785411784 liters, or about 3.785 liters.
How many liters are in 5 gallons?
Five US liquid gallons equal 18.92705892 liters, or about 18.9271 liters.
Are US and UK gallons the same?
No. This converter uses the US liquid gallon. The UK Imperial gallon is a different, larger unit.
How do I convert liters to gallons?
Divide liters by 3.785411784. For example, 10 L is about 2.6417 US liquid gallons.