A "cup" of coffee in the US is usually 4 fluid ounces, brewed using 5 fluid ounces of water. Coffee carafes used with drip coffee makers, e.g. Black and Decker models, have markings for both water and brewed coffee as the carafe is also used for measuring water prior to brewing. A 12-cup carafe, for example, has markings for 4, 6, 8, 10, and 12 cups of water or coffee, which correspond to of water or of brewed coffee respectively, the difference being the volume absorbed by the coffee grounds and lost to evaporation during brewing.
Australia, Canada, New Zealand, and some other members of the Commonwealth of Nations, being former British colonies that have since metricated, employ a "metric cup" of 250millilitres. Although derived from the metric system, it is not an SI unit. A "coffee cup" is 1.5 dL, and is occasionally used in recipes; in older recipes, cup may mean "coffee cup". It is also used in the US to specify coffeemaker sizes. A "12-cup" US coffeemaker makes 57.6 US customary fluid ounces of coffee, which is equal to 6.8 metric cups of coffee.
In the United Kingdom the standard cup was set at 10 imperial fluid ounces, or half an imperial pint. The cup was rarely used in practice, as historically most kitchens tended to be equipped with scales and ingredients were measured by weight, rather than volume.
International
Similar units in other languages and cultures are sometimes translated "cup", usually with various values around to of a litre.
In Latin America, the amount of a "cup" varies from country to country, using a cup of 200mL, 250mL, and the US legal or customary amount.
Japanese cup
The traditional Japanese unit equated with a "cup" size is the gō, legally equated with litres in 1891, and is still used for reckoning amounts of rice and sake. The Japanese later defined a "cup" as 200 mL.
Russian cup
included two cup sizes, one of which, the "charka", was usually used for alcoholic drinks and measured 123 mL, while another, "stakan" was twice as big at 246 mL and used for other liquids. Since metrication, the charka was informally redefined as 100 mL, acquiring a new name of "stopka", while there are currently two widely used glass sizes of 250 and 200 mL.
Dry measure
In Europe, recipes normally weigh non-liquid ingredients in grams rather than measuring volume. For example, where an American recipe might specify "1 cup of sugar and 2 cups of milk", a European recipe might specify "200 g sugar and 500 mL of milk". A precise conversion between the two measures takes into account the density of the ingredients, and some recipes specify both weight and volume to facilitate this conversion. Many European measuring cups have markings that indicate the weight of common ingredients for a given volume.
