| Centiliters (cL) | Kiloliters (kL) |
|---|---|
| 1 Centiliter | 0.00001 kL |
| 2 Centiliters | 0.00002 kL |
| 3 Centiliters | 0.00003 kL |
| 4 Centiliters | 0.00004 kL |
| 5 Centiliters | 0.00005 kL |
| 10 Centiliters | 0.0001 kL |
| 20 Centiliters | 0.0002 kL |
| 25 Centiliters | 0.00025 kL |
| 50 Centiliters | 0.0005 kL |
| 100 Centiliters | 0.001 kL |
| Reference | Centiliters (cL) | Kiloliters (kL) |
|---|---|---|
| A teaspoon | 0.5 cL | 0.000005 kL |
| A can of soft drink | 33 cL | 0.00033 kL |
| A wine bottle | 75 cL | 0.00075 kL |
| A bathtub | 15000 cL | 0.15 kL |
| An Olympic swimming pool | 250000000 cL | 2500 kL |
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.
The kilolitre is a unit of volume equal to one thousand litres, and therefore exactly one cubic metre. Its symbol is kL. The two names describe the same quantity, and which one appears depends entirely on the trade and the country: water utilities in the southern hemisphere say kilolitre where European ones say cubic metre.
Household water is where most people meet it. Australian, New Zealand and South African water bills are issued in kilolitres, tariffs are set as a price per kilolitre with rising blocks for heavier use, and drought restrictions are expressed as an allowance of so many kilolitres per household per quarter. A typical family uses between fifty and two hundred a year, so the annual bill fits in three digits.
Because the unit equals a cubic metre, it also carries an unusually direct physical meaning. A kilolitre of water weighs one tonne and would fill a cube one metre on each side, so a household allowance of a hundred kilolitres is a hundred tonnes of water, delivered, pumped and treated. Stating it that way is one reason the unit appears in conservation campaigns as often as on invoices.
Bulk liquid logistics uses it for cargo. A flexible tank fitted inside a shipping container carries around twenty-four kilolitres of wine, juice or edible oil, road tankers are rated in kilolitres, and depot storage is planned in thousands of them. Japanese petroleum statistics are published in kilolitres rather than in barrels, which makes Japanese energy figures awkward to compare with those of countries that use the barrel.
Industry generally prefers the cubic metre for the same quantity, because it is the coherent SI form and because it multiplies cleanly with metres of head, square metres of surface and other dimensional quantities. The kilolitre survives where the substance being measured is a liquid sold to the public, which is exactly where a name containing the word litre reads more naturally.
Converting is trivial in one direction and awkward in the other. One kilolitre is one cubic metre exactly and a thousand litres exactly, but 264.2 United States gallons and 220 imperial gallons, and about 6.29 barrels of oil, none of which are round numbers.
One kilolitre equals 1000 litres, 1 cubic metre, about 264.2 US gallons, or about 220 imperial gallons.