Conversion from 2 US Gallons to US Dry pints

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.

Information about the US Dry pint (pt)

The United States dry pint is a unit of volume equal to 550.610471 millilitres, or 33.6 cubic inches. Its symbol is pt. It belongs to a separate American measuring system used for produce and grain rather than for liquids, and it is about sixteen per cent larger than the United States liquid pint of 473 millilitres.

Two parallel chains exist because two kinds of goods were once measured differently. Liquids descend from the wine gallon of 231 cubic inches, while dry goods descend from the Winchester bushel of 2150.42 cubic inches, a corn measure standardised in medieval England. Dividing the bushel by four gives a peck, by thirty-two a dry quart, and by sixty-four a dry pint, and none of those figures has any relation to the liquid chain.

Berries are where the unit is still met. Blueberries, raspberries and strawberries are sold in American markets in pint and quart baskets, and the basket is a dry measure. A pint of blueberries is therefore 551 millilitres of fruit, not 473, and a shopper comparing that basket with a pint of cream is comparing two different quantities under one name.

Nothing on a label resolves the ambiguity. Both are written pt, both are called a pint, and the word gives no clue as to which chain is meant. In practice the contents decide: if it pours, it is liquid measure, and if it is heaped, it is dry. That rule is reliable but it is nowhere written down, which is why converted American recipes so often disagree with one another.

Its existence is a survival from selling by bulk. Before cheap accurate scales, grain, apples, potatoes and shellfish were sold by filling a stamped measure and levelling it off, and the whole dry chain from bushel down to pint served that trade. Almost all of it has now been replaced by weight, and United States produce regulations increasingly specify pounds instead.

For conversion, the safest approach is to abandon the name entirely. A dry pint is 551 millilitres, a dry quart 1101, a peck 8.81 litres and a bushel 35.24. Writing the metric figure removes an ambiguity that the English word carries and cannot shed.

One United States dry pint equals 550.61 millilitres, 33.6 cubic inches, half a US dry quart, or about 1.164 US liquid pints.