Imperial Gallon (imp gal)
The imperial gallon is the UK liquid volume unit and is about 20 percent larger than the US gallon.
- Origin
- Defined in 1824 from the volume of ten pounds of water, now fixed as 4.54609 L.
- Where it is used
- Used in UK and Commonwealth fuel, water and tank capacity figures.
- Relation to SI
- 1 imp gal = 4.54609 L exactly.