The UK gallon (imperial gallon) equals exactly 4.54609 liters, about 20% larger than the US gallon, and remains the standard fuel measurement in the United Kingdom and some Commonwealth nations. British fuel efficiency is expressed in miles per imperial gallon, which yields higher numbers than the US equivalent. One UK gallon equals approximately 1.201 US gallons.

The US cup is a volume unit equal to 8 US fluid ounces or approximately 0.2366 liters, the standard measurement in American recipes and cookbooks. When a recipe calls for 'one cup of flour' or 'half a cup of sugar,' it refers to this specific volume, not a drinking vessel of arbitrary size. One US cup equals exactly 236.588 milliliters.