Volume
US liquid gallons to liters
One US liquid gallon is 231 cubic inches, and since the inch has an exact metric definition this factor is exact rather than measured. Multiply, then keep the digits.
The Formula
L = gal x 3.785411784
One US liquid gallon is 231 cubic inches, and since the inch has an exact metric definition this factor is exact rather than measured. Multiply, then keep the digits.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| gal | Volume in US liquid gallons | US liquid gallons | The count, not the volume. Each unit is 231 cubic inches. |
| 3.785411784 | Liters in one US liquid gallon | liters per gallon | Exact. It follows from 231 cubic inches and the metric definition of the inch. |
| L | Volume in liters | liters | Multiply by 1000 to express the same volume in milliliters. |
What Each Symbol Means
galUS liquid gallons
Volume in US liquid gallons
The count, not the volume. Each unit is 231 cubic inches.
3.785411784liters per gallon
Liters in one US liquid gallon
Exact. It follows from 231 cubic inches and the metric definition of the inch.
Lliters
Volume in liters
Multiply by 1000 to express the same volume in milliliters.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to convert gallons to liters page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Convert Gallons To Liters, filed under Unit Conversion. Every number the guide produces comes from substituting into this one line.