1 Imperial Gallon equals 4.54609 Liters.
| Imperial Gallon (imp gal) | Liter (L) |
|---|---|
| 0.001 imp gal | 0.00454609 L |
| 0.01 imp gal | 0.0454609 L |
| 0.1 imp gal | 0.454609 L |
| 1 imp gal | 4.54609 L |
| 2 imp gal | 9.09218 L |
| 5 imp gal | 22.7305 L |
| 10 imp gal | 45.4609 L |
| 25 imp gal | 113.652 L |
| 50 imp gal | 227.305 L |
| 100 imp gal | 454.609 L |
| 500 imp gal | 2,273.05 L |
| 1,000 imp gal | 4,546.09 L |
To convert Imperial Gallons to Liters, multiply the value by 4.54609. This factor comes from the ratio of the two units' definitions: one Imperial Gallon equals 4.54609 Liters.
For example: 1 Imperial Gallon = 4.54609 Liters, and 10 Imperial Gallons = 45.4609 Liters.
To convert in the reverse direction — from Liters to Imperial Gallons — multiply by 0.219969.
The imperial gallon is a unit of volume defined as exactly 4.54609 liters — approximately 20% larger than the US liquid gallon. Established in Britain in 1824 when Parliament standardized weights and measures across the Empire, it was designed to be exactly the volume occupied by 10 pounds of distilled water at a specific temperature and pressure, linking volume to mass in a way analogous to the metric system's liter-kilogram relationship.
The imperial gallon was the standard volume unit for fuel across the British Empire and remains the official fuel measure for the United Kingdom (though the UK transitioned to liters for most fuel sales in 1994) and Canada (which switched to liters in 1979). Today, its most visible remaining use is fuel economy in the UK, where it continues to be quoted as "miles per gallon" on official government testing standards, even though pumps dispense fuel in liters.
When comparing fuel efficiency across countries, the US and UK figures are not directly comparable because their gallons differ by about 20%. A US car rated at 40 mpg (US gallons) would achieve about 48 mpg in UK (imperial) gallons — a difference large enough to mislead if the distinction is missed. Canada quotes fuel consumption as liters per 100 km, which is cleaner but requires dividing to compare with either mpg figure.
The liter (L) is the fundamental practical unit of volume in the metric system, defined as exactly one cubic decimeter (a cube 10 cm on each side). Originally defined in 1795 as the volume of one kilogram of pure water at 4°C — the temperature of maximum water density — the liter was later refined to exactly 0.001 cubic meters. A liter of water weighs almost exactly one kilogram, a relationship that makes mental calculation intuitive across cooking, chemistry, and everyday life.
The liter dominates fluid commerce worldwide: bottled water, milk, juice, cooking oil, and soft drinks are sold in liters across most countries. Fuel economy is measured in liters per 100 kilometers throughout Europe and much of Asia. Engine displacement — the total swept volume of all cylinders — is measured in liters (or sometimes cubic centimeters for smaller engines): a "2.0 L engine" is a familiar car specification.
In chemistry, the liter is the standard for solution concentrations: molarity (moles per liter), normality, and mass concentrations all use the liter as the reference volume. The abbreviation "L" (uppercase, to avoid confusion with the numeral 1) is preferred in most modern usage, though "l" (lowercase) remains in some older texts. One liter equals 1,000 milliliters, 100 centiliters, or approximately 1.057 US liquid quarts.
1 Imperial Gallon equals 4.54609 Liters.
To convert Imperial Gallons to Liters, multiply by 4.54609. For example, 1 Imperial Gallon = 4.54609 Liters.
1 Liter equals 0.219969 Imperial Gallons.