An imperial gallon is exactly 4.54609 liters.
Imperial gallons to Oil barrels Converter — imp gal to bbl
Convert Imperial gallon (imp gal) to Oil barrel (bbl) using the exact conversion factor (1 imperial gallon = 0.0285940459 oil barrel). See the formula, worked examples, conversion table, history, and common uses.
Imperial gallons to Oil barrels converter
Converter
Volume Converter
Convert metric, US customary, imperial, cooking, dry, and industrial volume units.
Context values
Some unit families need one extra value for a physically accurate result.
An oil barrel is 42 US gallons.
Result = input x 0.00454609 / 0.1589872949.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Imperial gallons to Oil barrels
Imperial gallon and Oil barrel appear side by side at fuel pumps and on beverage labels, since the US measures liquids in gallons while most of the world uses liters. Imperial gallon is most often used for uk fuel and beverage measurement (historically; uk now primarily uses liters for retail).
Formula
oil barrels = imperial gallons × 0.0285940458454
This factor comes from each unit's defined relationship to the category's base unit: 1 imperial gallon equals 0.00454609 base units, and 1 oil barrel equals 0.158987294928 base units, so dividing one by the other gives the direct imperial gallon-to-oil barrel factor of 0.0285940458454.
Simple example
1 imp gal × 0.02859404585 = 0.0285940459 bbl
1 imperial gallon = 0.0285940459 oil barrels.
Real-world example
10 imp gal × 0.02859404585 = 0.2859404585 bbl
10 imperial gallons = 0.2859404585 oil barrels.
Conversion table
| Imperial gallon (imp gal) | Oil barrel (bbl) |
|---|---|
| 1 imp gal | 0.0285940459 bbl |
| 5 imp gal | 0.1429702292 bbl |
| 10 imp gal | 0.2859404585 bbl |
| 25 imp gal | 0.7148511461 bbl |
| 50 imp gal | 1.429702292 bbl |
| 100 imp gal | 2.859404585 bbl |
Reverse conversion: Oil barrel to Imperial gallon
0.0285940459 bbl × 34.97231575 = 1.000000002 imp gal
0.0285940459 oil barrels = 1.000000002 imperial gallons.
imperial gallons = oil barrels × 34.9723157544
For a page dedicated to this direction, see Oil barrel to Imperial gallon.
Understanding the Imperial gallon
Imperial gallon (imp gal) measures volume. The imperial gallon is defined as exactly 4.54609 liters, about 20% larger than the US gallon. It is classified as a UK/imperial customary unit.
Where it's used: United Kingdom, Canada (some contexts), and other Commonwealth countries
Imperial gallon vs. US gallon. Britain's 1824 Weights and Measures Act defined a new gallon based on 10 pounds of water, replacing the old wine gallon the US had already adopted — leaving the US (3.785 L) and imperial (4.546 L) gallons about 20% apart today.
Uses of the Imperial gallon today
- UK fuel and beverage measurement (historically; UK now primarily uses liters for retail)
- Commonwealth country liquid measurement in some contexts
History of the Imperial gallon
The imperial gallon was created by Britain's Weights and Measures Act of 1824, defined as the volume of 10 pounds of water, replacing several inconsistent older English gallon definitions (wine gallon, ale gallon, corn gallon) with one standard.
Historical origin. Imperial gallon was not the invention of a single named person; it developed through the process described above.
Understanding the Oil barrel (bbl)
An oil barrel is 42 US gallons.
Imperial gallon — sources
- UK Weights and Measures Act 1824 — Establishes the imperial gallon definition.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many oil barrels are in 1 imperial gallon?
1 imperial gallon equals 0.0285940459 oil barrels, using the exact defined conversion factor rather than an estimate.
How do I convert imperial gallon to oil barrel?
Multiply the imperial gallon value by 0.02859404585. The converter above does this instantly to whatever precision you set.
How do I convert oil barrel back to imperial gallon?
Use the reverse factor: 1 oil barrel equals 34.97231575 imperial gallons. You can also use the swap control in the converter above to flip the direction instantly.
What is a imperial gallon?
Imperial gallon (imp gal) measures volume. The imperial gallon is defined as exactly 4.54609 liters, about 20% larger than the US gallon. It is classified as a UK/imperial customary unit.
What is a oil barrel?
Oil barrel (bbl) is a unit of volume.
Is the imperial gallon to oil barrel conversion exact?
Yes. The imperial gallon is defined as exactly 4.54609 liters, about 20% larger than the US gallon. That fixed definition is what the converter above uses, so any rounding you see is a display choice, not a limitation of the math.
What is the difference between imperial gallon vs. us gallon?
Britain's 1824 Weights and Measures Act defined a new gallon based on 10 pounds of water, replacing the old wine gallon the US had already adopted — leaving the US (3.785 L) and imperial (4.546 L) gallons about 20% apart today.
Where is the imperial gallon still used today?
United Kingdom, Canada (some contexts), and other Commonwealth countries