An imperial gallon is exactly 4.54609 liters.
Imperial gallons to Gigaliters Converter — imp gal to GL
Convert Imperial gallon (imp gal) to Gigaliter (GL) using the exact conversion factor (1 imperial gallon = 4.54609e-9 gigaliter). See the formula, worked examples, conversion table, history, and common uses.
Imperial gallons to Gigaliters 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.
Gigaliter is 1000000000 liter units.
Result = input x 0.00454609 / 1e+6.
Volume uses the cubic meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Imperial gallons to Gigaliters
Imperial gallon and Gigaliter 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
gigaliters = imperial gallons × 4.54609e-9
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 gigaliter equals 1000000 base units, so dividing one by the other gives the direct imperial gallon-to-gigaliter factor of 4.54609e-9.
Simple example
1 imp gal × 4.54609e-9 = 4.54609e-9 GL
1 imperial gallon = 4.54609e-9 gigaliters.
Real-world example
10 imp gal × 4.54609e-9 = 4.54609e-8 GL
10 imperial gallons = 4.54609e-8 gigaliters.
Conversion table
| Imperial gallon (imp gal) | Gigaliter (GL) |
|---|---|
| 1 imp gal | 4.54609e-9 GL |
| 5 imp gal | 2.273045e-8 GL |
| 10 imp gal | 4.54609e-8 GL |
| 25 imp gal | 1.136522e-7 GL |
| 50 imp gal | 2.273045e-7 GL |
| 100 imp gal | 4.54609e-7 GL |
Reverse conversion: Gigaliter to Imperial gallon
4.54609e-9 GL × 219969248.3 = 1 imp gal
4.54609e-9 gigaliters = 1 imperial gallon.
imperial gallons = gigaliters × 219969248.299
For a page dedicated to this direction, see Gigaliter 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 Gigaliter (GL)
Gigaliter is 1000000000 liter units.
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 gigaliters are in 1 imperial gallon?
1 imperial gallon equals 4.54609e-9 gigaliters, using the exact defined conversion factor rather than an estimate.
How do I convert imperial gallon to gigaliter?
Multiply the imperial gallon value by 4.54609e-9. The converter above does this instantly to whatever precision you set.
How do I convert gigaliter back to imperial gallon?
Use the reverse factor: 1 gigaliter equals 219,969,248.3 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 gigaliter?
Gigaliter (GL) is a unit of volume.
Is the imperial gallon to gigaliter 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