Convert pt to cup

A US pint is 473 ml and an imperial pint is 568 ml — a fifth larger. This is the single most consequential difference between the two systems for anybody following a recipe or ordering a drink.

A US customary cup is 236.6 ml, but American nutrition labels use a "legal" cup of exactly 240 ml, and a metric cup in Australia is 250. A recipe scaled up tenfold will show which one it assumed.

Going this way is a multiplication, and by a whole number: one US pint is 2 US cups, exactly, and 2 is the definition rather than a measurement that came close.

That makes it one of the few conversions worth doing in your head, and it makes the answer checkable: divide back and you must land on the number you started with, exactly, with no remainder to explain away.

The US pint is two different sizes wearing one name. This page uses the US one, which is 2 cup; the imperial one still used in the UK and Ireland is 2.4019 cup — larger by 20.1 %.

That gap is the awkward size: far too big to ignore in a recipe, and far too small to spot from the answer alone. If your figure came from a British source, take the second number, and note that the fluid ounce is the one unit here where the imperial measure is the smaller of the two.

This is the one step on the ladder that cannot produce a fraction. Doubling a pint count gives cups and doubling anything whole gives something whole: 1 pint is 2 cups, 3 pints is 6, 7 pints is 14. Every other conversion in US volume can leave you with a sixteenth or a third of something; this one cannot, which is why it is the rung most people have right.

It also means a pint figure carries no information a cup figure does not, so the reason to convert is practical rather than arithmetic. Recipes are written in cups because that is the size of the measure in the drawer; liquids are sold in pints because that is the size of the carton on the shelf. The conversion is the translation between the shop and the kitchen, and it happens with the carton already open.

A pint carton of heavy cream, buttermilk or half-and-half holds exactly the 2 cups a recipe asks for, and that exactness is the problem. There is no allowance in it for what stays behind on the walls of the carton, for the spoonful tasted, or for the recipe that wants 2 cups plus a little to brush the top. A carton that measures short is usually not underfilled; it is a carton that has been poured from once already.

Where the amount matters, measure into a jug rather than pouring straight from the carton into the bowl. Whipping cream is the usual example: the volume roughly doubles as it whips, so a pint that started as 2 cups becomes about 4 cups of whipped cream, and a recipe asking for "2 cups whipped cream" wants a half-pint carton rather than a pint. Which side of the whipping the measurement was taken on is the thing to establish before buying.

Recipes built on containers halve badly, because half a container is not a shape anybody measures. A pint of stock halves to 1 cup cleanly enough, but the ingredients around it rarely do: 3 tablespoons halves to 1½, ¾ cup halves to 6 tablespoons, and a single egg halves to about 2 tablespoons of beaten egg. Working the liquid down from pints to cups first gives the rest of the recipe a scale to follow.

The tablespoon is what makes a half-recipe workable. One cup is 16 tablespoons, so any awkward fraction has a whole-number tablespoon equivalent: a third of a cup is 5⅓ tablespoons, an eighth is 2. Converting the odd measures into tablespoons and leaving the liquid in cups is faster than trying to find fractional cup lines that do not exist on the measure.

It is close for water and only for water. A US pint of water weighs 473 grams, which is 1.04 pounds — near enough for the saying to have survived. Change the liquid and it drifts immediately: a pint of milk is about 1.07 pounds, a pint of honey about 1.5, a pint of cooking oil a little under one.

For dry ingredients measured by volume it stops being useful entirely. Two cups of all-purpose flour weighs around 240 to 250 grams, barely over half a pound, because flour is mostly air by volume. Anywhere a recipe gives both a volume and a weight for the same ingredient, they will disagree with the rhyme, and the weight is the figure that reproduces.

An imperial pint holds 20 imperial fluid ounces — 568.26 ml — against 16 US fluid ounces, or 473.18 ml, for a US pint. The imperial version is a fifth larger, and converted into US cups it comes to 2.4 rather than 2. That is the single largest discrepancy in customary volume, and it is carried by a word that looks identical in both systems.

It shows up in drinks more than in food. A British pint glass really does hold more beer than an American one, and a cocktail or punch recipe scaled from a British source will be short by 20 per cent on its main liquid if converted at two cups to the pint. British recipes for food usually weigh their ingredients, which is why the imperial pint is mostly a bar and brewing problem rather than a baking one.

Below the pint the customary system stops using the word. A half pint is 1 cup and is sold as a half pint; a quarter pint is ½ cup and nobody calls it that — it is a half cup or 4 fluid ounces. The gill, the traditional quarter pint, has disappeared from American use entirely and survives only in old recipes and in some spirits measures.

That naming gap is worth knowing when reading anything old. A recipe calling for a gill wants 4 US fluid ounces, half a cup, and if it is British it wants a quarter of an imperial pint, which is 5 imperial fluid ounces — about 142 ml, or ⅗ of a US cup. Two rare units and two systems in one word is more ambiguity than the quantity is usually worth, and modern reprints often silently pick one.

Pints are sold as portions as often as they are used as measurements, and the portion sizes have drifted away from the unit. Ice cream containers sold as pints are 16 fluid ounces and hold 2 cups, but the container that used to be a half gallon is now commonly 1.5 quarts, and the pint is one of the few sizes that has stayed honest. A pint glass in a bar is a 16 fl oz US pint, sometimes with the foam counted.

Where the pint is a serving, converting it to cups is a way of seeing the portion clearly. Two cups of ice cream, two cups of beer, two cups of a smoothie sold in a pint cup — all the same volume, and all of them look larger stated that way than they do on the container. That is the most useful thing this conversion does outside a kitchen.