False friends US part 4

gallon ['gælən] is a unit of measurement of liquids, so just about fits with the “food” theme. It is used in both Britain and the US to measure liquids like milk, beer or petrol (of course, this is “gas” in the US!). So what’s the problem, you say? Well, it isn’t the same amount: a US gallon is smaller than a British one. This is because gallons are 8 pints, and pints are made up of fluid ounces, which are almost the same volume on both sides of the Atlantic. So? “Almost” doesn’t make much difference to a gallon, surely? No, it doesn’t – that difference can be ignored. However, a British pint contains 20 fluid ounces, whereas an American pint only has 16. This makes a British pint 125% of the volume of a US one. This difference comes from the fact that units of measurements were only standardised (in both countries) in the 19th century, after US independence. So drinking US or British pints of beer can make a difference to the hangover the next day, and putting British or US gallons of petrol (or gas) in your car can determine whether you reach your destination or not.