Last updated: August 2026
Convert Gallons to Liters (gal to L)
Whether you're measuring fuel, cooking ingredients, or home brewing supplies, converting between US gallons and metric liters is a common task. Use our free calculator to instantly get the exact liquid volume conversion.
The Conversion Formula
The standard conversion is simple: Liters = Gallons × 3.78541. Keep in mind that this calculator uses the US fluid gallon standard, which is most common in North America.
Frequently Asked Questions
There are approximately 3.78541 liters in one US liquid gallon.
To convert US gallons to liters, multiply the volume in gallons by 3.78541. For example, 5 gallons equals about 18.9 liters.
No, a UK (imperial) gallon is larger than a US gallon. One imperial gallon equals about 4.54609 liters.
Divide by 3.78541, or multiply by about 0.264172. One liter equals roughly 0.264172 US gallons.
It defaults to the US liquid gallon (3.78541 liters). If you need UK/imperial gallons instead, multiply by 4.54609 liters per gallon rather than the US figure.
Yes. The same tool also covers milliliters, cubic meters, teaspoons, tablespoons, fluid ounces, cups, pints, and quarts — just change the 'From' and 'To' dropdowns.
Some conversions don't land on a clean number. The calculator displays up to 6 decimal places and trims trailing zeros, so you get a precise figure without an unnecessarily long string of zeros.