Liter (L)
The liter, symbol L, is a metric unit of volume equal to one cubic decimeter (dm³). First introduced in France in 1795, it became the standard for everyday liquid measurements. While technically not a SI base unit, the liter is accepted for use with the SI due to its practicality. One liter equals 1,000 milliliters and 0.001 cubic meters, and is used worldwide as a unit of volume. It is utilized in cooking, chemistry, and other applications where standard volume measurement is required.
Imperial Gallon (imp gal)
The imperial gallon, shown as imp gal, is a British unit equal to 4.54609 liters. It came from English wine and drink measures in the 1800s and became official in 1824. The imperial gallon was used throughout the British Empire and is still used in the UK and some other countries for fuel and beverages. The liter is now used almost everywhere, but the imperial gallon still exists because of custom and local use.