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.
Cubic Meter (m³)
The cubic meter (m³) is the official SI unit for volume, representing the space within a cube whose sides are each one meter in length. Established as part of the metric system in the late 1700s, it acts as a foundation for quantifying large volumes. A single cubic meter equals 1,000 liters and is routinely used across engineering, construction, shipping, and the environmental sector for consistent volume calculations. Its use promotes accuracy and standardization in global commerce, scientific research, and industrial processes.