Gallons to Liters Converter
Convert US liquid or Imperial gallons to liters using exact factors, with examples and gallon definitions.
Let’s convert it.
Swap unitsDecimals welcome. The answer updates as you type.
5 gal × 3.785411784 ≈ 18.927059 L
Understanding gallons and liters
To convert gallons to liters, multiply by the size of the selected gallon: 3.785411784 L for a US liquid gallon or 4.54609 L for an Imperial gallon.
What are gallons (gal)?
A gallon (gal) measures volume. A US liquid gallon contains 128 US fluid ounces; an Imperial gallon contains 160 Imperial fluid ounces. The fluid ounces also differ in size.
What are liters (L)?
A liter (L) is a metric unit of volume containing 1,000 milliliters. Converting to liters gives one shared unit for comparing the two gallon systems.
How to use this converter
- Select US liquid or Imperial gallons.
- Enter the number of gallons shown on the container or specification.
- Read the equivalent volume in liters.
The conversion formula
liters = US gallons × 3.785411784; liters = Imperial gallons × 4.54609
A worked example
A 5 US liquid gallon container holds 5 × 3.785411784 = 18.92705892 L. A 5 Imperial gallon container holds 22.73045 L.
A tank described as 5 gallons can have two different capacities. Confirm the gallon system in the manufacturer’s specification before calculating its volume in liters.
Quick conversion table
Values are rounded for readability. This table uses US liquid gallons; choose Imperial in the calculator for UK gallons.
| gallons (gal) | liters (L) |
|---|---|
| 1 | 3.785412 |
| 5 | 18.927059 |
| 10 | 37.854118 |
| 25 | 94.635295 |
| 50 | 189.270589 |
| 100 | 378.541178 |
Common questions
Does one gallon equal four liters?
Only as a rough estimate for a US liquid gallon. Its exact volume is 3.785411784 L; an Imperial gallon is 4.54609 L.
Why are US and Imperial results different?
An Imperial gallon is about 20% larger than a US liquid gallon, so an equal number of Imperial gallons holds more liquid.