Equivalent in Liters:
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How many liters are in a gallon?
There are 3.78541 liters in one US gallon. The gallon is primarily used in the United States, while the liter is the standard metric unit of volume used internationally.
How to convert gallons to liters
To convert US gallons to liters, multiply the number of gallons by 3.78541.
Liters = Gallons × 3.78541
For example, to convert 5 gallons to liters:
5 × 3.78541 = 18.927 liters
To convert in the other direction — liters to gallons — multiply by 0.264172:
Gallons = Liters × 0.264172
You can also use the liters to gallons converter for the reverse calculation.
US gallon vs. Imperial gallon
There are two common definitions of the gallon:
- US gallon: 3.78541 liters — used in the United States
- Imperial gallon: 4.54609 liters — used in the UK and some Commonwealth countries
This converter uses the US gallon. To convert Imperial gallons to liters, multiply by 4.54609 instead.
Gallons to Liters Conversion Table
Quick reference for common gallon to liter conversions (US gallons):
| US Gallons | Liters |
|---|---|
| 1 gal | 3.785 L |
| 2 gal | 7.571 L |
| 3 gal | 11.356 L |
| 4 gal | 15.141 L |
| 5 gal | 18.927 L |
| 10 gal | 37.854 L |
| 15 gal | 56.781 L |
| 20 gal | 75.708 L |
| 25 gal | 94.635 L |
| 50 gal | 189.271 L |
| 100 gal | 378.541 L |
When do you need to convert gallons to liters?
Common situations where gallons-to-liters conversion is needed:
- Fuel purchases abroad: US drivers travelling internationally will find fuel sold in liters. Knowing how many liters are in a gallon helps you understand how much fuel you're buying and what it costs per gallon equivalent.
- Aquariums and fish tanks: Tank sizes are listed in gallons in the US but in liters elsewhere. Converting helps when buying equipment, calculating water treatments, or comparing tank sizes across brands.
- Water storage and tanks: Rain barrels, storage tanks, and water heaters are often specified in gallons in the US but liters in metric countries.
- Recipes and homebrewing: Beer and wine recipes may specify volumes in either gallons or liters depending on where they originate. Accurate conversion is important when scaling batches.
- Vehicle fuel economy: US fuel efficiency is measured in miles per gallon (MPG), while most countries use liters per 100 km. Converting between the two requires knowing the gallon-to-liter relationship.
FAQs
There are 3.78541 liters in one US gallon. To convert gallons to liters, multiply the number of gallons by 3.78541.
There are 0.264172 US gallons in one liter. To convert liters to gallons, multiply the number of liters by 0.264172.
There are 18.927 liters in 5 US gallons (5 × 3.78541 = 18.927).
There are 37.854 liters in 10 US gallons (10 × 3.78541 = 37.854).
A US gallon equals 3.78541 liters, while a UK (Imperial) gallon equals 4.54609 liters. The UK gallon is approximately 20% larger than the US gallon.
Yes, a US gallon is significantly larger than a liter. One US gallon equals approximately 3.785 liters, making a gallon about 3.8 times larger than a liter.