How do I convert US gallon (gal) to Imperial gallon (gal UK)?

1 gal equals 0.832674 gal_uk using SI-based conversion and precise factors.

What is the formula to convert US gallon (gal) to Imperial gallon (gal UK)?

This is a linear unit conversion using a constant factor between units.

How can I share a direct gal to gal_uk result?

Use the shareable URL: https://measurecalc.com/convert/us-gallon-to-imperial-gallon

Convert US gallon (gal) to Imperial gallon (gal UK)

Q: Is US gallon (gal) to Imperial gallon (gal UK) conversion exact?

Yes, it uses exact definitions or standardized constants (e.g., 1 in = 25.4 mm).

Category: Volume

Value From To Precision

0.832674 gal_uk

1 gal = 0.832674 gal_uk

High-precision rounding: 6 decimals

How to convert us gallon (gal) to imperial gallon (gal uk)

Volume measures the space a substance occupies. SI uses cubic meters and liters; customary units like gallons, quarts, and pints persist in recipes, fuel, and containers. Accurate volume work often requires temperature and density considerations (e.g., for fuels).

This converter calculates US gallon (gal) to Imperial gallon (gal UK) values by using the correct conversion rule for the Volume category. For linear units, standardized factors are used. For temperature, the calculator applies the proper formula with offsets.

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Quick conversion table

Handy values for US gallon (gal) to Imperial gallon (gal UK). Click a value to open that exact result.

US gallon (gal)	Imperial gallon (gal UK)
1	0.832674
0.5	0.416337
2.5	2.081685
10	8.326742

Conversion formula

Linear unit conversions use standardized factors; many are exact by definition (e.g., 1 in = 25.4 mm, 1 ft = 0.3048 m).

Common mistakes

Mixing US gallons (3.785 L) with Imperial gallons (4.546 L).
Assuming kitchen ‘cup’ equals the same volume in every country.

Unit facts

US gallon (gal): The US gallon is exactly 3.785411784 L; used for fuel, beverages, and bulk liquids.
Imperial gallon (gal UK): The Imperial gallon is exactly 4.54609 L; still used in the UK for beer, milk, and fuel economy.

About US gallon (gal)

US gallon (gal)

Exactly 3.785411784 L. Used for fuel, containers, and recipes in the US. Beware of imperial gallon differences.

History: US defined the gallon separately from the British imperial revision; modern value is exact.

About Imperial gallon (gal UK)

Imperial gallon (UK)

Exactly 4.54609 L. Still appears in UK fuel economy (mpg) and historical tables.

History: Set by the 1824 Weights and Measures Act; differs notably from the US gallon.

Frequently asked questions

How many Imperial gallon (gal UK) are in one US gallon (gal)?

1 US gallon (gal) equals 0.832674 Imperial gallon (gal UK).

Is US gallon (gal) to Imperial gallon (gal UK) conversion exact?

Many unit conversions are exact by definition, while others use standardized conversion constants.

What is the fastest way to convert US gallon (gal) to Imperial gallon (gal UK)?

Enter a value in US gallon (gal), choose Imperial gallon (gal UK) as the target unit, and the calculator will instantly return the result.

Convert US gallon (gal) to other units

gal → bbl Barrel (oil, bbl)
gal → ft3 Cubic foot (ft³)
gal → in3 Cubic inch (in³)
gal → m3 Cubic meter (m³)
gal → cup Cup (US)
gal → l Liter (L)

Convert other units to Imperial gallon (gal UK)

bbl → gal_uk Barrel (oil, bbl)
ft3 → gal_uk Cubic foot (ft³)
in3 → gal_uk Cubic inch (in³)
m3 → gal_uk Cubic meter (m³)
cup → gal_uk Cup (US)
l → gal_uk Liter (L)