Conversion from 4 US Liquid pints to Hectoliters

Information about the US Liquid pint (pt)

The United States liquid pint is a unit of volume equal to exactly 473.176473 millilitres. Its symbol is pt. It is sixteen United States fluid ounces and an eighth of a United States gallon. It is noticeably smaller than the imperial pint of 568 millilitres, because the American pint holds sixteen fluid ounces where the British one holds twenty.

That difference of four ounces is the whole story of the two pints. Both systems descend from the same medieval English measures, but Britain rebuilt its liquid chain in 1824 around a gallon of ten pounds of water, while the United States kept the older wine gallon of 231 cubic inches. The pint inherited the difference, and a British pint is now about a fifth larger than an American one.

The rhyme survives because the American pint fits it. A pint's a pound the world around works for the United States pint, since sixteen fluid ounces of water weigh 1.04 pounds, and it fails in Britain, where a pint of water weighs a pound and a quarter. The saying is a useful reminder that measurement rhymes travel worse than the measurements themselves.

Draught beer is where the difference becomes visible to travellers, and where American practice is looser than British. There is no federal requirement that a glass sold as a pint contain a pint, and the widely used sixteen-ounce shaker glass holds that volume only when filled to the brim, so a poured beer with a head contains less. Several states have legislated on the point precisely because the imperial system's verified glass has no American equivalent.

Domestic packaging uses it constantly. Milk, cream, ice cream and soft fruit are sold in pint containers, and a donated unit of blood is loosely called a pint although it is about 470 millilitres. Premium ice cream in a pint tub is one of the most recognisable retail formats in the country.

A separate United States dry pint of 551 millilitres exists for produce, and nothing in the word distinguishes it. A pint of cream and a pint of blueberries are therefore different quantities, differing by about sixteen per cent, which is the sort of detail that only becomes visible when someone tries to convert a recipe.

One United States liquid pint equals 473.176 millilitres, 16 US fluid ounces, 0.125 US gallons, or about 0.833 imperial pints.

Information about the Hectoliter (hL)

The hectolitre is a unit of volume equal to one hundred litres, or a tenth of a cubic metre. Its symbol is hL. It is the trading unit of the drinks industry and of much of agriculture, and although almost nobody outside those trades ever writes it, within them it is the number that appears on every contract, licence and annual report.

Brewing runs on it entirely. A brewery's capacity is stated in hectolitres a year, duty is assessed on hectolitres produced, and the large international groups report annual volumes in hundreds of millions of them. A standard keg holds half a hectolitre, so the unit also happens to match the physical container the trade moves, which is part of why it stuck.

Wine regulation is written in the same terms. European appellation rules cap yield in hectolitres per hectare, a figure that does more than any other single number to define the character of an appellation, since a low cap concentrates the fruit and a high one dilutes it. Production statistics, stocks and the surpluses that periodically trouble the European market are all counted the same way.

Grain trading uses the unit in an unexpected direction. The hectolitre weight, or test weight, is the mass of grain that fills one hectolitre, and it is a standard quality specification: milling wheat is typically bought at 76 to 80 kilograms per hectolitre, and a load below the contracted figure is downgraded. The measurement works because well-filled, undamaged grain packs more densely than shrivelled grain does.

Dairy and other bulk liquids follow. Milk collection, fruit juice processing, edible oil and cider are all recorded in hectolitres, because the quantities involved are too large for litres to read comfortably and too small for cubic metres to be precise enough for duty and quality purposes.

For scale, a hectolitre is a large domestic water tank, a household bath filled about one and a half times, or a barrel of oil and a half. It converts to 22 imperial gallons or 26.4 United States gallons, and to 0.1 cubic metres exactly, which is the quickest route into SI-based calculations.

One hectolitre equals 100 litres, 0.1 cubic metres, about 26.4 US gallons, or about 22 imperial gallons.