Cubic Foot (ft³)
A cubic foot (ft³) is a unit of volume in the imperial and US customary systems, defined as the amount of space enclosed by a cube with one-foot sides. It originated in English-speaking regions where it became a standard for measuring materials and space, especially in construction and trade. Today, the cubic foot remains common in American industries such as real estate, heating and cooling (HVAC), and the measurement of natural gas. It is equal to about 28.316 liters, allowing for practical use in both domestic and industrial settings. Even though most of the world uses metric units, the cubic foot maintains its significance in various technical and commercial fields.
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.