Volume conversion
US liquid gallon to Imperial gallon converter
Convert gal to imp gal instantly, choose the displayed precision, and verify the result with the formula and reference table below.
Imperial gallon (imp gal)
Rounded for display only; calculations retain full precision.
Rounding and precision rules
- Convr calculates first and rounds the displayed result only once, at the final step.
- The default is a maximum of 6 decimal places; trailing zeros are removed.
- Very small values that would appear as zero, and values of 10¹² or more, use scientific notation.
- Display precision is not measurement uncertainty. For scientific, engineering, or regulated work, retain only the digits justified by the source measurement.
Practical context
Understanding this conversion
This conversion is useful for comparing American and British tank capacities, fuel quantities, water use, and vehicle records that label both values simply as gallons.
The units are not interchangeable. A numerical capacity copied between gallon systems without conversion creates an error of roughly 20 percent relative to the US-gallon quantity.
Reviewed August 16, 2026.
Calculation
US liquid gallon to Imperial gallon formula
imp gal = gal × 0.832674
Calculations retain full precision and the result is rounded only for display.
Worked example
For 10 gal, the result is 8.326742 imp gal. Substitute 10 gal into the formula to obtain 8.326742 imp gal.
A numerical value expressed in imperial gallon is usually smaller than the same measurement expressed in us liquid gallon, because 1 gal equals 0.832674 imp gal.
US liquid gallon to Imperial gallon reference table
Common values rounded to a maximum of 6 decimal places.
| US liquid gallon (gal) | Imperial gallon (imp gal) |
|---|---|
| 1 gal | 0.832674 imp gal |
| 5 gal | 4.163371 imp gal |
| 10 gal | 8.326742 imp gal |
| 50 gal | 41.633709 imp gal |
| 100 gal | 83.267418 imp gal |
Understanding the units
About US liquid gallon and Imperial gallon
US liquid gallon (gal)
One us liquid gallon (gal) equals 3.785411784 L, the base relationship used for this volume conversion.
Imperial gallon (imp gal)
One imperial gallon (imp gal) equals 4.54609 L, the base relationship used for this volume conversion.
When this conversion is useful
US liquid gallon to Imperial gallon conversion is useful for recipes, beverage quantities, fuel volumes, laboratory measurements, and container capacities. It lets you compare the same volume or capacity across documents, tools, or standards that use different units.
Learn with Convr
Conversion guides
Metric vs Imperial Units: A Practical Comparison
Understand how metric, US customary, and Imperial units differ, where each system is used, and how to convert between them reliably.
Read guide →Everyday conversionsUS Gallons vs Imperial Gallons: What Is the Difference?
Compare US liquid gallons and Imperial gallons, understand their exact liter values, and avoid common fuel and recipe conversion errors.
Read guide →Answers at a glance
Frequently asked questions
How many Imperial gallons are in one US gallon?
One US liquid gallon is approximately 0.832674 Imperial gallon.
Which gallon is larger?
The Imperial gallon is larger. It equals 4.54609 liters, compared with 3.785411784 liters for the US liquid gallon.
How does Convr round US liquid gallon to Imperial gallon results?
Convr keeps full numeric precision during the calculation and rounds only the displayed result. The default is a maximum of 6 decimal places, with selectable precision on this page.
Can I convert negative or decimal us liquid gallon values?
Yes. The converter accepts positive, negative, decimal, and scientific-notation values. Negative values are physically meaningful for some scales, such as temperature, but not for every measured quantity.
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