Last updated: September 16, 2026
Quick answer: To convert US gallons to liters, multiply by 3.78541. So 5 gal = 18.9271 L.
Gallon (US) to Liter
Instantly convert gallon (us) to liter with fast, accurate, real-time results.
Gallons are the imperial unit of volume used for fuel and large containers in the US; liters are the metric unit used almost everywhere else. This converter uses the US gallon.
How to convert US gallons to liters
Multiply the number of US gallons by 3.785411784. One US gallon is defined as exactly 3.785411784 liters.
To go the other way, use the liters to gallons converter.
Step-by-step
- Write down the value in US gallons (for example, 5 gal).
- Multiply it by 3.78541.
- The result is the value in liters (5 gal = 18.9271 L).
- Round to the precision you need using the tool above.
Worked example
Convert 5 US gallons to liters:
So 5 US gallons is 18.9271 liters.
Us gallons to liters conversion table
| Us gallons (gal) | Liters (L) |
|---|---|
| 1 gal | 3.78541 L |
| 2 gal | 7.57082 L |
| 3 gal | 11.3562 L |
| 5 gal | 18.9271 L |
| 10 gal | 37.8541 L |
| 15 gal | 56.7812 L |
| 20 gal | 75.7082 L |
| 25 gal | 94.6353 L |
| 50 gal | 189.271 L |
| 100 gal | 378.541 L |
Understanding your result
The conversion is exact for the US gallon; any rounding is only from the decimals you display.
Accuracy & limitations
This uses the US liquid gallon (3.785411784 L exactly). The UK gallon is 4.54609 L — a different unit.
Frequently asked questions
How many liters are in a US gallon?
One US gallon equals 3.78541 liters.
How do I convert US gallons to liters?
Multiply by 3.78541. For example, 5 gal × 3.78541 = 18.9271 L.
What is 5 US gallons in liters?
5 US gallons is 18.9271 liters.
How do I convert liters back to US gallons?
Use the liters to gallons converter.
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Creator
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