Conversion from Centiliters to US Gallons

Information about the Centiliter (cL)

The centilitre is a unit of volume equal to one hundredth of a litre, or ten millilitres. Its symbol is cL, and the lower-case cl is also used. Unlike most centi-prefixed units it has a real commercial life, because it happens to be the size that suits drink labelling, and in several countries it is the form printed on almost every bottle.

Drink containers are its main employment. In France, Belgium, Italy and Spain a wine bottle is labelled 75 cL, a beer 33 or 50 cL, a soft drink 33 cL, and a spirits miniature 5 cL. The same containers carry 750 ml and 330 ml in Britain, Germany and most of the English-speaking world, which is why identical bottles appear to bear different numbers depending on where they were filled.

Bar measures follow the same split. A standard spirit serving is 4 cL in France and 2 or 4 cL in Germany and Austria, while Britain pours 25 or 35 millilitres and the United States uses fluid ounces. European cocktail recipes are written in centilitres throughout, so a classic proportion of six parts to three to one appears as 6 cL, 3 cL and 1 cL, which reads more cleanly than the millilitre equivalents.

There is no legal difference between the forms. European Union labelling rules accept millilitres, centilitres and litres, so the choice is a matter of national typographic habit rather than of regulation. Where centilitres are used, the number on a bottle stays between one and a hundred for every ordinary container size, which is exactly the range a prefix is supposed to deliver.

The unit is also easy to picture. Ten millilitres is two teaspoons, a generous mouthful of water, or the dose measure supplied with a bottle of cough syrup. A tablespoon is one and a half centilitres, an espresso is about three, and a wine glass poured to a standard measure is twelve to fifteen.

Converting between systems needs some care because a centilitre falls between the two customary small measures. It is 0.338 United States fluid ounces and 0.352 imperial fluid ounces, so neither reads as a round number, and drink volumes converted between Europe and North America almost always end up rounded rather than exact.

One centilitre equals 10 millilitres, 0.01 litres, about 0.338 US fluid ounces, or about 0.352 imperial fluid ounces.

Information about the US Gallon (gal US)

The United States gallon is a unit of volume equal to exactly 231 cubic inches, or 3.785411784 litres. Its symbol is gal US. It contains four quarts, eight liquid pints and 128 United States fluid ounces, and it is about a fifth smaller than the imperial gallon still used in Britain and Ireland.

It is older than its British rival. The figure of 231 cubic inches comes from the English wine gallon standardised in 1707 under Queen Anne, which was the common measure across the American colonies. When Britain abolished its several gallons in 1824 and replaced them with a single imperial gallon based on ten pounds of water, the United States simply kept the one it already had, and the two systems have diverged ever since.

Fuel makes it the most politically visible unit in American life. The price of a gallon of gasoline is quoted daily, watched by governments and used as shorthand for the cost of living, and vehicle efficiency is stated in miles per gallon on every window sticker. Because the American gallon is smaller, a car rated at 30 miles per gallon in the United States would be described as 36 in Britain, which is the same car and the same fuel.

The petroleum industry counts in a multiple of it. The barrel of crude oil is defined as 42 United States gallons, a figure fixed in the Pennsylvania oil fields in the 1860s when a 40-gallon barrel plus two gallons of allowance for leakage became the trade standard. Every published figure for world oil production and reserves rests on that convention.

Domestic quantities follow the same measure. Milk, paint, water for the garden, propane and swimming pool chemistry are all sold and dosed by the gallon in the United States, and a gallon of fresh water weighs 8.34 pounds against the imperial gallon's ten. That difference in weight is a useful check when a figure of uncertain origin needs to be identified.

Care with labelling matters when the two gallons meet. A liquid described simply as a gallon in an American document is 3.785 litres and in a British one 4.546, and nothing in the word itself distinguishes them. Writing gal US or specifying litres removes an ambiguity that has caused real errors in shipping, aviation and chemical dosing.

One United States gallon equals 3.785411784 litres, 231 cubic inches, 128 US fluid ounces, or about 0.833 imperial gallons.